Railways

From Britannica 11th Edition (1911)

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Railways. Railways had their origin in the tramways (q.v.) or wagon-ways which at least as early as the middle of the 16th century were used in the mineral districts of England round Newcastle for the conveyance of coal from the pits to the river Tyne for shipment. It may be supposed that originally the public roads, when worn by the cartage of the coal, were repaired by laying planks of timber at the bottom of the ruts, and that then the planks were laid on the surface of special roads or ways' formed between the collieries and the river. " The manner of the carriage," says Lord Keeper North in 1676, " is by laying rails of timber. .. exactly straight and parallel, and bulky carts are made with four rowlets fitting these rails, whereby the carriage is so easy that one horse will draw down four or five chaldrons of coals " (from io-6 to 13.2 tons). The planks were of wood, often beech, a few inches wide, and were fastened down, end to end, on logs of wood, or " sleepers," placed crosswise at intervals of two or three feet. In time it became a common practice to cover them with a thin sheathing or plating of iron, in order to add to their life; this expedient caused more wear on the wooden rollers of the wagons, and, apparently towards the middle of the 18th century, led to the introduction of iron wheels, the use of which is recorded on a wooden railway near Bath in 1734. But the iron sheathing was not strong enough to resist buckling under the passage of the loaded wagons, and to remedy this defect the plan, was tried of making the rails wholly of iron. In 1767 the Colebrookdale Iron Works cast a batch of iron rails or plates, each 3 ft. long and 4 in. broad, having at the inner side an upright ledge or flange, 3 in. high at the centre and tapering to a height of 22 in. at the ends, for the purpose of keeping the flat wheels on the track. Subsequently, to increase the strength, a similar flange was added below the rail. Wooden sleepers continued to be used, the rails being secured by spikes passing through the extremities, but about 1793 stone blocks also began to be employed--an innovation associated with the name of Benjamin Outram, who, however, apparently was not actually the first to make it. This type of rail (fig. i) was known as the plate-rail, tramway-plate or barrowway-plate - names which are preserved in the modern term " platelayer " applied to the men who lay and maintain the permanent way of a railway.

Another form of rail, distinguished as the edgerail, was first used on a line which was opened between Loughborough and Nanpantan in 1789. This line was originally designed as a " plateway " on the Outram system, but objections were raised to rails with upstanding ledges or flanges FIG. I.- being laid on the turnpike road which was crossed Plateat Loughborough on the level. In other cases Rail. this difficulty was overcome by paving or " causewaying " the road up to the level of the top of the flanges, but 1 " Another thing that is remarkable is their way-leaves; for, when men have pieces of ground between the colliery and the river, they sell leave to lead coals over their ground " (Roger North).

on this occasion William Jessop, of the Butterley Iron Works, near Derby, proposed to get over it by laying down two plates of iron, perfectly flat and level with the road but each having on its outside a groove 4 in. wide and 4 in. deep to control extra guiding wheels which were to be of somewhat larger diameter than the bearing wheels and to be affixed to them. The rest of the line was laid with what were substantially plate-rails placed on their edge instead of flat. These were cast in 3 ft. lengths, of a double-flanged section, and for the sake of strength they were " fish-bellied " or deeper in the middle than at the ends. At one end of each rail the flange spread out to form a foot which rested on a cross sleeper, being secured to the latter by a spike passing through a central hole, and above this foot the rail was so shaped as to form a socket into which was fitted the end of the next rail. Each length was thus fastened to a sleeper at one end, while at the other it was socketed into the end of its fellow. This method, however, was not found satisfactory: the projecting feet were liable to be broken off, and in 1799 or 1800 Jessop abandoned them, using instead separate cast-iron sockets or chairs, which were fastened to the sleepers and in which the rails were supported in an upright position. In the first instance he proposed to place the guiding wheels outside the bearing wheels, and the Nanpantan line was laid on this plan with a width of 5 ft. between the guide wheels; but before it was opened he decided not only to cast the guiding wheels and bearing wheels in one piece but also to put the former inside the rails, arguing that with this arrangement the edge-rails themselves would keep the wheels in position on the axles, whereas with that first contemplated fastenings would have been required for them (fig. 2). Jessop thus produced what was virtually the flanged wheel of to-day, having the flanges inside the rails,. and further, it is said, established what has become the standard gauge of the world, 4 ft. 82 in., or 5 ft. minus the width of two of his rails.

These two systems of constructing railways - the plate-rail and the edge-rail - continued to exist side by side until well on in the 19th century. In most parts of England the plate-rail was preferred, and it was used on the Surrey iron railway, from Wandsworth to Croydon, which, sanctioned by parliament in 1801, was finished in 1803, and was the first railway available to the public on payment of tolls, previous lines having all been private and reserved exclusively for the use of their owners. In South Wales again, where in 1811 the railways in connexion with canals, collieries and iron and copper works had a total length of nearly 150 miles, the plate-way was almost universal. But in the north of England and in Scotland the edge-rail was held in greater favour, and by the third decade of the century its superiority was generally established. The manufacture of the rails themselves was gradually improved. By making them in longer lengths a reduction was effected in the number of joints - always the weakest part of the line; and another advance consisted in the substitution of wrought iron for cast iron, though that material did not gain wide adoption until after the patent for an improved method of rolling rails granted in 1820 to John Birkinshaw, of the Bedlington Ironworks, Durham. His rails were wedge-shaped in section, much wider at the top than at the bottom, with the intermediate portion or web thinner still, and he recommended that they should be made 18 ft. long, even suggesting that several of them might be welded together end to end to form considerable lengths. They were supported on sleepers by chairs at intervals of 3 ft., and were fish-bellied between the points of support. As used by George Stephenson on the Stockton & Darlington and Whitstable & Canterbury lines they weighed 28 lb per yard. On the Liverpool && Manchester railway they were usually 12 ft. or 15 ft. long and weighed 35 lb to the yard, and they were fastened by iron wedges to chairs weighing 15 or 17 lb each. The chairs were FIG. 2.- Rail.

in turn fixed to the sleepers by two iron spikes, half-round wooden cross sleepers being employed on embankments and stone blocks 20 in. square by io in. deep in cuttings. The fishbellied rails, however, were found to break near the chairs, and from 1834 they began to be replaced with parallel rails weighing 50 lb to the yard.

The next important development in rail design originated in America, which, for the few lines that had been laid up to 1830, remained content with wooden bars faced with iron. In that year Robert Livingston Stevens (1787-1856), devised for the Camden & Amboy railway a rail similar as to its top to those in use in England, but having a flat base or foot by which it was secured to the sleepers by hook-headed spikes, without chairs (fig. 3); he had to get the first lot of these rails, which were 15 ft. long and weighed 36 lb to the yard, manufactured in England, since there were then no mills in America able to roll them. This type, which is often known as the Vignoles rail, after Charles Blacker Vignoles (1793-1875), who re-invented it in England in 1836, is in general use in America and on the continent of Europe. The bridge-rail (fig. 4) - so called because it was FIG. 3. - FlatFIG. 4. - Bridge Bottomed Rail. Rail.

first laid on bridges - was supported on continuous longitudinal sleepers and held down by bolts passing through the flanges, and was employed by I. K. Brunel on the Great Western railway, where, however, it was abandoned after the line was converted from broad to standard gauge in 1892. In the double-headed rail (fig. 5), originated by Joseph Locke in 1837, and first laid on the Grand Junction railway, the two tables were equal. This rail was more easily rolled than others, and, being reversible, was in fact two rails in one. But as it was laid in cast-iron chairs the lower table was exposed to damage under the hammering of the traffic, and thus was liable to be rendered useless as a running surface. In consequence the bull-headed rail (fig. 6) FIG. 5. - DoubleFIG. 6. - Bull Headed Rail. Headed Rail.

was evolved, in which the lower table was made of smaller size and was intended merely as a support, not as a surface to be used by the wheels. There was a waste of metal in these early rails owing to the excessive thickness of the vertical web, and subsequent improvements have consisted in adjusting the dimensions so as to combine strength with economy of metal, as well as in the substitution of steel for wrought iron (after the introduction of the Bessemer process) and in minute attention to the composition of the steel employed.

It was found, naturally, that the rails would not rest in their chairs at the joints, but were loosened and bruised at the ends by the blows of the traffic. The fish-joint was therefore devised in 1847 by W. Bridges Adams, the intention being by " fishing " the joints to convert the rails into continuous beams. In the original design two chairs were placed, one under each rail, a few inches apart, as in fig. 7. The joint was thus suspended between the two chairs, and two keys of iron, called " fishes," fitting the side channels of the rails, were driven in on each side between the chairs and the rails. In subsequent modifications the fishes were, as they continue to be, bolted to and through the rails, the sleepers being placed rather further apart and the joint being generally suspended between them.

The iron tramway or railway had been known for half a century and had come into considerable use in connexion with collieries and quarries before it was realized that for the carriage FIG. 7. - The original Fish-Joint of W. Bridges Adams.

of general merchandise it might prove a serious competitor to the canals, of which a large mileage had been constructed in Great Britain during that period. In the article on " Railways " in the Supplement to the Encyclopaedia Britannica, published in 1824, it is said: "It will appear that this species of inland carriage [railways] is principally applicable where trade is considerable and the length of conveyance short; and is chiefly useful, therefore, in transporting the mineral produce of the kingdom from the mines to the nearest land or water communication, whether sea, river or canal. Attempts have been made to bring it into more general use, but without success; and it is only in particular circumstances that navigation, with the aid either of locks or inclined planes to surmount the elevations, will not present a more convenient medium for an extended trade." It must be remembered, however, that at this time the railways were nearly all worked by horse-traction, and that the use of steam had made but little progress. Richard Trevithick, indeed, had in 1804 tried a high-pressure steam locomotive, with smooth wheels, on a plate-way near Merthyr Tydvil, but it was found more expensive than horses; John Blenkinsop in 1811 patented an engine with cogged wheel and rack-rail which was used, with commercial success, to convey coal from his Middleton colliery to Leeds; William Hedley in 1813 built two locomotives - Puffing Billy and Wylam Dilly - for hauling coal from Wylam Colliery, near Newcastle; and in the following year George Stephenson's first engine, the Blucher, drew a train of eight loaded wagons, weighing 30 tons, at a speed of 4 m. an hour up a gradient of 1 in 450. But, in the words of the same article, " This application of steam has not yet arrived at such perfection as to have brought it into general use." The steam locomotive, however, and with it the railways, soon began to make rapid progress. On the Stockton & Darlington railway, which was authorized by parliament in 1821, animal power was at first proposed, but on the advice of Stephenson, its engineer, steam-engines were adopted. This line, with three branches, was over 38 m. in length, and was in the first instance laid with a single track, passing-places being provided at intervals of a quarter of a mile. At its opening, on the 27th of September 1825, a train of thirtyfour vehicles, making a gross load of about go tons, was drawn by one engine driven by Stephenson, with a signalman on horseback in advance.. The train moved off at the rate of from to to 12 m. an hour, and attained a speed of 15 m. an hour on favourable parts of the line. A train weighing 92 tons could be drawn by one engine at the rate of 5 m. an hour. The principal business of the new railway was the conveyance of minerals and goods, but from the first passengers insisted upon being carried, and on the 10th of October 1825 the company began to run a daily coach, called the " Experiment," to carry six inside, and from fifteen to twenty outside, making the journey from Darlington to Stockton and back in two hours. The fare was is., and each passenger was allowed to take baggage not exceeding 14 lb weight. The rate for carriage of merchandise was reduced from 5d. to one-fifth of a penny per ton per mile, and that of minerals from 7d. to ti-d. per ton per mile. The price of coals at Darlington fell from 18s. to 8s. 6d. a ton.

The example of the Stockton & Darlington line was followed by the Monklands railway in Scotland, opened in 1826, and several other small lines - including the Canterbury & Whitstable, worked partly by fixed engines and partly by locomotives - quickly adopted steam traction. But the Liverpool & Manchester railway, opened in 1830, first impressed the national mind with the fact that a revolution in the methods of travelling had really taken place; and further, it was for it that the first high-speed locomotive of the modern type was invented and constructed. The directors having offered a prize of £500 for the best engine, trials were held on a finished portion of the line at Rainhill in October 1829, and three engines took part - the Rocket of George and Robert Stephenson, the Novelty of John Braithwaite and John Ericsson, and the Sanspareil of Timothy Hackworth. The last two of these engines broke down under trial, but the Rocket fulfilled the conditions and won the prize. Its two steam cylinders were 8 in. in diameter, with a stroke of 162 in., and the driving wheels, which were placed in front under the funnel, were 4 ft. 82 in. in diameter. The engine weighed 44 tons; the tender following it, 3 tons 4cwt.; and the two loaded carriages drawn by it on the trial, 9 tons i 1 cwt.: thus the weight drawn was 124 tons, and the gross total of the train 17 tons. The boiler evaporated 184 cub. ft., or 114 gals., of water an hour, and the steam pressure was 50 lb per square inch. The engine drew a train weighing 13 tons 35 m. in 48 minutes, the rate being thus nearly 44 m. an hour; subsequently it drew an average gross load of 40 tons behind the tender at 13.3 m. an hour. The Rocket possessed the three elements of efficiency of the modern locomotive - the internal water-surrounded fire-box and the multitubular flue in the boiler; the blast-pipe, by which the steam after doing its work in the cylinders was exhausted up the chimney, and thus served to increase the draught and promote the rapid combustion of the fuel; and the direct connexion of the steam cylinders, one on each side of the engine, with the two driving wheels mounted on one axle. Of these features, the blast-pipe had been employed by Trevithick on his engine of 1804, and direct driving, without intermediate gearing, had been adopted in several previous engines; but the use of a number (25) of small tubes in place of one or two large flues was an innovation which in conjunction with the blast-pipe contributed greatly to the efficiency of the engine. After the success of the Rocket, the Stephensons received orders to build seven more engines, which were of very similar design, though rather larger, being four-wheeled engines, with the two driving wheels in front and the cylinders behind; and in October 1830 they constructed a ninth engine, the Planet, also for the Liverpool & Manchester railway, which still more closely resembled the modern type, since the driving wheels were placed at the fire-box end, while the two cylinders were arranged under the smoke-box, inside the frames. The main features of the steam locomotive were thus established, and its subsequent development is chiefly a history of gradual increase in size and power, and of improvements in design, in material and in mechanical construction, tending to increased efficiency and economy of operation.

In America the development of the locomotive dates from almost the same time as in England. The earliest examples used in that country, apart from a small experimental model constructed by Peter Cooper, came from England. In 1828, on behalf of the Delaware && Hudson Canal Company, which had determined to build a line, 16 m. long, from Carbondale to Honesdale, Pennsylvania, Horatio Allen ordered three locomotives from Messrs Foster & Rastrick, of Stourbridge, and one from George Stephenson. The latter, named the America, was the first to be delivered, reaching New York in January 1829, but one of the others, the Stourbridge Lion, was actually the first practical steam locomotive to run in America, which it did on the 9th of August 1829. The first American-built loccmotive, the Best Friend, of Charleston, was made at the West Point Foundry, New York, in 1830, and was put to work on the South Carolina railroad in that year. It had a vertical boiler, and was carried on four wheels all coupled, the two cylinders being placed in an inclined position and having a bore of about 6 in. with a stroke of 16 in. It is reported to have hauled 40 or 50 passengers in 4 or 5 cars at a speed of 16-21 m. an hour. After a few months of life it was blown up, its attendant, annoyed by the sound of the escaping steam, having fastened down the safety-valve. A second engine, the West Point, also built at West Point Foundry for the South Carolina railroad, differed from the Best Friend in having a horizontal boiler with 6 or 8 tubes, though in other respects it was similar. In 1831 the Baltimore & Ohio Company offered a prize of $4000 for an American engine weighing 32 tons, able to draw 15 tons at 15 m. an hour on the level: it was won by the York of Messrs Davis & Gartner in the following year. Matthias W. Baldwin, the founder of the famous Baldwin Locomotive Works in Philadelphia, built his first engine, Old Ironsides, for the Philadelphia, Germantown & Morristown railroad; first tried in November 1832, it was modelled on Stephenson's Planet, and had a single pair of driving wheels at the firebox end and a pair of carrying wheels under the smoke-box. His second engine, the E. L. Miller, delivered to the South Carolina railroad in 1834, presented a feature which has remained characteristic of American locomotives - the front part was supported on a four-wheeled swivelling bogie-truck, a device, however, which had been applied to Puffing Billy in England when it was rebuilt in 1815.

The Liverpool & Manchester line achieved a success which surpassed the anticipations even of its promoters, and in consequence numerous projects were started for the construction of railways in various parts of Great Britain. In the decade following its opening nearly 2000 m. of railway were sanctioned by parliament, including the beginnings of most of the existing trunk-lines, and in 1840 the actual mileage reached 1331 m. The next decade saw the " railway mania." The amount of capital which parliament authorized railway companies to raise was about 42 millions on the average of the two years 1842-1843, 174 millions in 1844, 60 millions in 1845, and 132 millions in 1846, though this last sum was less than a quarter of the capital proposed in the schemes submitted to the Board of Trade; and the wild speculation which occurred in railway shares in 1845 contributed largely to the financial crisis of 1847. In 1850 the mileage was 6635, in 1860 it was 10,410, and in 1870 it was 15,310. The increase in the decade1860-1870was thus nearly 50%, but subsequently the rate of increase slackened, and the mileages in 1880, 1890 and 1900 were 17,935, 20,073 and 21,855. In the United States progress was more rapid, for, beginning at 2816 in 1840, the mileage reached 9015 in 1850, 30,600 in 1860, 87,801 in 1880, and 198,964 in 1900. Canada had no railway till 1853, and in South America construction did not begin till about the same time. France and Austria opened their first lines in 1828; Belgium, Germany, Russia, Italy and Holland in the succeeding decade; Switzerland and Denmark in 1844, Spain in 1848, Sweden in 1851, Norway in 1853, and Portugal in 1854; while Turkey and Greece delayed till 1860 and 1869. In Africa Egypt opened her first line (between Alexandria and Cairo) in 1856, and Cape Colony followed in 1860. In Asia the first line was that between Bombay and Tannah, opened in 1853, and in Australia Victoria began her railway system in 1854 (see also the articles on the various countries for further details about their railways).

A railway line across North America was first completed in 1869, when the Union Pacific, building from the Missouri river at Omaha (1400 m. west of New York), met the Central Pacific, which built from San Francisco eastwards, making a line 1848 m. long through a country then for the most part uninhabited. This was followed by the Southern Pacific in 1881, from San Francisco to New Orleans, 2489 miles; the Northern Pacific, from St Paul to Portland, Ore., in 1883; the Atchison, Topeka & Santa Fe, from Kansas City to San Diego; and the Great Northern from St Paul to Seattle and New Westminster in 1893. Meanwhile the Canadian Pacific, a true transcontinental line, was built from Montreal, on Atlantic tide-water, to the Pacific at Vancouver, 2906 m. But these lines have been dwarfed since 1891 by the Siberian railway, built by the Russian government entirely across the continent of Asia from Cheliabinsk (1769 m. by rail east of St Petersburg) to Vladivostok, a distance of 4073 m., with a branch from Kharbin about Soo m. long to Dalny and Port Arthur. The main line was finished in 1902, except for a length of about 170 m. in very difficult country around the south end of Lake Baikal; this was constructed in 1904, communication being maintained in the interval by ferry-boats, which conveyed all the carriages of a train across the lake, more than 40 m., when the ice permitted. A transcontinental line was long ago undertaken across South America from Buenos Aires to Valparaiso, where the continent is only about goo m. wide. The last section through the Andes was finished in 1910. (H. M. R.) General Statistics Mileage.-At the close of 1907 there were approximately 601,808 miles of railway in the world, excluding tramways. On the whole, the best statistical source for this information is the annual computation published by the Archiv fiir Eisenbahnwesen, the official organ of the Prussian Ministry of Public Works; but the figure quoted above utilizes the Board of Trade returns for the United Kingdom and the report of the Interstate Commerce Commission for the United States. In the United States and in certain other countries, a fiscal year, ending on the 30th of June or at some other irregular period, is substituted for the calendar year.

The partition of this total between the principal geographical divisions of the world is given in Table I.

Table I.-Mileage Of The World Miles. Miles.

Europe. 199,371 Africa 18,516 America ... 309,974 Australia 17,766 Asia 56,181 Table II., classifying the mileage of Europe, shows that Russia has taken the lead, instead of Germany, as in former years. If the Asiatic portions of the Russian Empire were given in the same table, the total Russian mileage would appear nearly as large as that of Germany and Italy together.

Table Ii.-Railways Of Europe In 1907 Total. 199,371 In the United States railway mileage now tends to increase at the rate of slightly over 5000 miles a year, which is about 2 ° o on the present main line mileage. In the ' eighties, the country passed through a period of competitive building, which was productive of much financial disaster. Thus, in 1882, 11,569 in. were built-an addition equivalent to more than I I % of mileage then existing-and in 1887, 12,876 m. were built. Unjustifiable railway expansion had much to do with the American commercial panics of 1884 and 1893. After the reconstruction period of the 1893 panic, however, the tendency for a number of years was to spend larger sums in bettering existing railways rather than in new extensions. The decade from 1896 until 1905, inclusive, saw huge sums spent on yards, passing tracks, grade reduction, elimination of curves, substitution of large locomotives and cars for small ones, &c. During those ten years, the route mileage increased 34,991 m., or 17%, while the mileage of second, third, fourth and yard tracks and sidings increased 32,666 m., or nearly 57%. The number of locomotives increased 12,407, or 35%, and the number of freight cars, 545,222, or 42%. Moreover, the average tractive power per locomotive and the average capacity per freight car advanced greatly in this period, although specific figures cannot be given.

Thus it may fairly be said that the railway system of the United States was reconstructed between 1896 and 1905, so far as concerns rails, sleepers, ballast and the general capacity of a given group of lines to perform work. About 1905, however, a new tendency became apparent. At that time the so-called transcontinental railways, connecting the Pacific coast of the United States with the central portions of the country, and thus with the group of railways reaching the Atlantic seaboard, consisted of five railways within the borders of the United States, and one in Canada. In Canada the Canadian Pacific was the only transcontinental line, extending from St John, on the bay of Fundy, and from Quebec, on the river St Lawrence, to Vancouver, on the strait of Georgia, the distance from St John to Vancouver being approximately 3379 m. Within the boundaries of the United States the northernmost of the transcontinental lines was the Great Northern railway, extending from a point opposite Vancouver, B.C., and from Seattle, Wash., to Duluth, on Lake Superior, and to St Paul and Minneapolis, Minn., where connexion through to Chicago was made over an allied line,. the Chicago, Burlington & Quincy, owned jointly by the Great Northern and the Northern Pacific.

Next, south of the Great Northern, lay the Northern Pacific railway, starting on the west from Portland, Ore., and from Seattle and Tacoma, Wash., and extending east to Duluth, St Paul and Minneapolis by way of Helena, Mont. The Central Pacific-Union Pacific route to the coast, with its important affiliated companies, the Oregon Short Line and the Oregon Railroad & Navigation Company, extended from San Francisco, Cal., and Portland, Ore., to Omaha, Neb., by way of Salt Lake City; the Atchison, Topeka & Santa Fe extended from San Francisco and Los Angeles, Cal., to Chicago and to Galveston, Tex.; while the Southern Pacific had. its line from San Francisco and Los Angeles to Galveston and New Orleans, running for the greater part of the distance just north of the Mexican border.

Thus it will be observed that the five great cities of the Pacific coast-Seattle and Tacoma, Wash., Portland, Ore., and San Francisco and Los Angeles, Cal.-were already well supplied with railways; but the growth of the fertile region lying west of the transcontinental divide was most attractive to American railway builders; and railways serving this district, almost all of them in trouble ten years before, were showing great increases in earnings. In 1903 the Gould lines determined to enter this Pacific territory. Hitherto the western terminus of this group of lines had been Salt Lake City, Utah; by the exceedingly bold construction of the Western Pacific from Salt Lake City to Oakland, Cal., opposite San Francisco, an additional line to the Pacific coast was provided, having low grades and being in all respects well adapted for cheap operation.

Shortly after the plans were announced for building the Western Pacific, the Chicago, Milwaukee & St Paul also decided to extend west. Before that time the St Paul had been a great local railway, operating primarily in the Dakotas, Minnesota, Iowa, Wisconsin and Illinois; but by the construction of a long arm from the Missouri river to Spokane, Seattle and Tacoma, it became a transcontinental line of the first importance, avoiding the mistakes of earlier railway builders by securing a line with easy gradients through the most favourable regions.

At the same time that these two extensions were being undertaken by old and well-established railways, a new company-the Kansas City, Mexico && Orient-was engaged in constructing a line almost due south-west from Kansas City, Mo., to the lower part of the gulf of California in Mexico; while an additional independent line was under construction from Denver in a north-westerly direction towards the Pacific coast. The guarantee for this activity may be illustrated by a single fact: the combined building operations, in 1908, of San Francisco, Seattle, Portland, Los Angeles, Spokane and Salt Lake City exceeded the combined building operations of Philadelphia, Pittsburg, Kansas City, Boston, Baltimore and Cincinnati during the same year. San Francisco spent more in new permanent structures than Philadelphia, and Seattle spent more than Pittsburg.

Recent American railway development, viewed in its larger aspects, has thus been characterized by what may be described as the rediscovery of the Pacific coast. How far this movement will extend it is impossible to say; it is certain, however, that it will be enormously important in re-aligning trade conditions in the United States, Canada and Mexico.

Table III. illustrates the railway mileage in the continent of America at the close of 1907.

Table Iii.-Railways Of America In 1907 Total. 309,974 Outside the United States and Canada, the most interesting American developments are in Mexico and Argentina, these countries Miles.

Germany 36,066 Austria-Hungary,including Bosnia and Herzegovina 25,853 GreatBritain and Ireland 23,108 France 29,717 EuropeanRussia, includ ing Finland 36,280 Italy.. 10,312 Belgium. 4,874 Holland. 2,230 Switzerland. 2,763 Spain 9,228 having nearly the same amount of railway mileage. In Mexico the national government is carrying out a consistent policy of developing its railway lines. It has succeeded in restoring the credit of these enterprises, and is proceeding with care and skill to form the lines into an efficient transportation system. In Argentina about 15% of the railways are owned and operated by the government, the balance being in the hands of private companies, largely controlled in England. Development of these lines has been primarily an extension from the large cities in the East to the agricultural districts in the West, but a change of great importance was brought about in 1910 by the completion of the last tunnel on the Argentine Transandine Railway, which serves to connect Santiago, Valparaiso and the other great cities of the west coast with Buenos Ayres, Montevideo, Bahia, Rio de Janeiro and the other great cities of the east coast. Naturally the company named does not reach all of these points, but its line across the Andes supplies the indispensable link of communication, in the absence of which the east coast towns and the west coast towns have hitherto been as widely separated as if they had been located on different continents-indeed, far more widely separated in point of time and of freight charges than Great Britain and the United States.

Table IV. shows as closely as possible the railway route mileage open in Asia at the close of 1907.

Table Iv.-Railways Of Asia In 1907 Miles.

Central Russia in Asia. 2,808 Siberia and Man churia . 5,565 China.. 4,1624,162 Korea . 688 Japan. 5,013 British India. 29,89329,893 Persia. 33 Asia Minor, Syria, Arabia and Cyprus 2,930 Portuguese East Indies 51 Total. 56,181 Although more than half of the total mileage of Asia is in British India, it is probable that the greatest proportionate gains in the near future will be in China, Siberia and Manchuria, and Central Russia in Asia. In proportion to its population China has the least railway development of any of the great countries of the world; the probability that its present commercial awakening will extend seems large, and in that case it will need a vast increase in its interior communications.

In Africa, it will be seen by Table V. that the railway mileage in the British possessions amounts to almost five-sixths of the total.

Total. 18,516 The so-called Cape-to-Cairo route shows occasional extensions, particularly in the opening up of new country in Central Africa by the Rhodesian railway system. The Rhodesian railway system in 1910 had penetrated north of Broken Hill, which is just above the fifteenth parallel of south latitude, while the Egyptian railway system had reached Gondokoro, located close to the fifth parallel of north latitude. The intervening distance, through country exceedingly unhealthy for white men, and therefore promising no traffic except raw materials, does not seem a likely field for rapid railway extension.

In Australia the increase in railway mileage in the five years ending December 31st, 1907 was about 7%-a small proportion as compared with America, Asia or Africa. The greatest increase, both relative and absolute, was in Queensland; the smallest in South Australia, which added only 24 m. during the five years. Yet the mileage open per Io,000 inhabitants in Australia, as a whole, far surpasses that in any other of the broad geographical divisions.

Table Vi.-Railways Of Australia In 1907 Miles. Miles.

Total 19,855 Table VII. illustrates the mileage open to the end of 1907 per loo sq. m. of territory and per 10,000 inhabitants. It will be observed that Belgium leads all the countries of the world in what may be called its railway density, with the United Kingdom a far-distant second in the list, and Persia last. In railway mileage per io,000 inhabitants, however, Queensland, in the Australian group, reports a figure much greater than any other country; while at the other end of the list Persia holds the record for isolation.

Table Vii.-Miles Open At The End Of 1907 Europe America, 1907 Per 100 Per 10,000 sq. miles. inhabitants.

Asia, 1907 Per loo Per 10,000 sq. miles. inhabitants.

Central Russia in Asia. P3 3.6 Siberia and Manchuria 0-II 9.8 China 0I 0.12 Korea. 0.8 o.68 Japan I I British India. 1.4 I.0 Ceylon.. 2.3 1.6 Persia 0.005 0.04 Asia Minor, Syria, Arabia, Cyprus 0.5 1.5 Portuguese Indies. 3.5 0'9 Malay Archipelago. 1.9 8.8 Dutch Indies o6 0.5 Siam 2.. 0.16 o6 Africa, 1907 Per 100 Per 10,000 sq. miles. inhabitants.

Egypt Algiers and Tunis Cape Colony .

Natal ..

Transvaal.. Orange Colony Complete estimates for the balance of ' No accurate returns for Central America, Greater and Lesser Antilles and Dutch Guiana.

2 Estimates of area and population incomplete for Cochin China, Cambodia, Annam, Tonkin, Pondicherry, Malacca and Philippines.

Miles. Malay States. 636 Dutch East Indies 1,5091,509 Siam. 571 Ceylon. 561 Cochin China Cambodia Annam Tonkin 1,761 Pondicherry Malacca Philippines. Po o8 I 3 3.5 II. I.8 Africa not available.

3.5 216 .

12.6 15.7 42.6 Australia. 1907 Capital. - The total construction capital invested in the railways of the world in 1907 was estimated by the Archiv fur Eisenbahnwesen at £8,986,150,000; the figure is necessarily incomplete, though it serves as a rough approximation. This total was divided nearly evenly between the countries of Europe and the rest of the world. The United States of America, with a capital of £3,059,800,000 invested in its railways on the 30th of June 1906, was easily ahead of every other country, and in 1908 the figure was increased to £ 3,443, 02 7, 68 5, of which £2,636,569,089 was in the hands of the public. On a route-mileage basis, however, the capital cost of the British railway system is far greater than that of any other country in the world, partly because a vast proportion of the lines are double, treble or even quadruple, partly because the safety requirements of the Board of Trade and the high standards of the original builders made actual construction very costly.

The total paid-up railway capital of the United Kingdom amounted, in 1908, to £1,310,533,212, or an average capitalization of £56,476 per route mile, though it should be noted that this total included £196,364,618 of nominal additions through " stock-splitting," &c. Per mile of single track, the capitalization in England and Wales, Scotland, Ireland and the United Kingdom, is shown in Table VIII.

Table Viii.-Paid-Up Capital, 1908 The table excludes sidings, because they cannot fairly be compared with running tracks, mile for mile. Yet the mileage of sidings in the United Kingdom amounted to 14,353 in 1908, and the cost of constructing them was probably not far from £60,000,000.

On a single-track-mile basis, the following comparison may be made between apparent capital costs in Great Britain and the United States: - Single-Track Paid-up Capital Mileage. per Mile.

United Kingdom, 1908.39,316 £ 33,333 United States, 1908.254,192 10,372 2 1 he figures for the United States are from the report of the Interstate Commerce Commission for the year ended 30th of June 1908, and comprise mileage of first, second, third and fourth tracks, and paid-up capital in the hands of the public only. The British figures are from the Board of Trade returns for the calendar year 1908. In comparing the figures, it should be noted that main line mileage in the Eastern states, as for example that of the Pennsylvania railroad and the New York, New Haven & Hartford, does not differ greatly in standards of safety or in unit cost from the best British construction, although improvement work in America is charged to income far more liberally than it has been in England. But there are long stretches of pine loam in the South where branch lines can be, and are, built and equipped for £2400 or less per mile, while the construction of new main line in the prairie region of the West ought not to cost more than £4000 per single-track-mile, under present conditions.

The problem of the early railway builders in the United States was to conquer the wilderness, to build an empire, and at the same time to bind the East to the West and the North to the South. There can be little doubt but that the United States would long ago have disintegrated into separate, warring republics, had they not been bound together by railways, and standards of safety were 1 These figures are derived from a total. They are not exact, but may be taken as representing an approximation correct within one per cent.

2 Dollars to pounds sterling @ 4.87.4.87.

rightly subordinated to the main task to be accomplished. Conquest is not usually bloodless, whether achieved at the van of a marching column or at the head of a hastily-built railway, and the process under which the American railway system took form left the way open for a distressing record of accidents to the traveller and the railway servant. But as traffic becomes more dense, year by year, the rebuilding process is constant, and American railway lines are gradually becoming safer.

In Europe the average route-mile capital is £27,036, and Table IX. shows the differences between various countries.

Table Ix.-Route-Mile Capital In Europe Statistical Study of Railway Operation. - The study of railway operation through statistics has two distinct aspects. It has been well said that statistics furnish the means by which the railway manager disciplines his property; this is the aspect of control. On the other hand, the banker, the government official and the economist use railway statistics to obtain information which may be characterized as static rather than dynamic. Both uses ultimately rest upon comparison of the observed data from a certain property with the observed data from other properties, or with predetermined standards of performance.

In general, the British working unit supplied as public information has always been the goods-train-mile and the passengertrain-mile, these figures being the products of the number of trains into the number of miles they have travelled. In America, the basic units have been the ton-mile and the passenger-mile, and these figures are now required to be furnished to the Interstate Commerce Commission and to most of the state commissions as well. Both the British manager and the American manager, however, are supplied with a considerable number of daily, weekly and monthly reports, varying on different railways, which are not made public. The daily sheets usually include a summarized statement of the performance of every train on the line, covering the amount of business done, the destination of the loads, &c. For a number of years there has been a movement in Great Britain to require the inclusion of ton-mile statistics in the stated returns to the Board of Trade, but most railway managers have objected to the change on the ground that their own confidential information was already adequate for purposes of control, and that ton-mile statistics would require additional clerical force to a costly extent. The Departmental Committee of the Board of Trade, sitting in 1909 to consider railway accounting forms, while recommending ton-miles to the careful consideration of those responsible for railway working in Great Britain, considered the question of their necessity in British practice to be still open, and held that, at all events, they should not be introduced under compulsion.

References.-A nnual Reports of the Interstate Commerce Commission; Poor's Manual of Railroads (annual, New York); Statistical Abstract of the United States (annual, Washington, published by the U. S. Bureau of Statistics); A. T. Hadley, Railroad Transportation, Its History and Laws (New York, 1885); E. R. Johnson, American Railway Transportation (New York, 1908); L. G. McPherson, Railroad Freight Rates (New York, 1909); S. Daggett, Railroad Reorganization (Boston, 1908); M. L. Byers, Economics of Railway Operation (New York, 1908); E. R. Dewsnup (ed.), Railway Organization and Working (Chicago, 1906); Interstate Commerce Commission; Rate Regulation Hearings before the U.S. Senate Committee (Washington, 5 vols., 1905); and on current matters, The Official Railway Guide (monthly, New York, the Railroad Age Gazette (weekly, New York) and the Commercial and Financial Chronicle (weekly, New York). (R. Mo.) Economics And Legislation It was at one time an axiom of law and of political economy that prices should be determined by free competition. But in the development of the railway business it soon became evident that no such dependence on free competition was possible, either in practice or in theory. This difficulty is not peculiar to railways; but it was in the history of railway economy and railway control that certain characteristics which are now manifesting themselves in all directions where large investments of fixed capital are involved were first brought prominently to public notice.

For a large number of those who use a railway, competition in its more obvious forms does not and cannot exist. Independent carriers cannot run trains over the same line and underbid one another in offering transportation services. It would be practically impossible for a line thus used by different carriers to be operated either with safety, or with economy, or with the advantage to the public which a centralized management affords. It is equally impossible for the majority of shippers to enjoy the competition of parallel lines. Such duplication of railways involves a waste of capital. If parallel lines compete at all points, they cause ruin to the investors. If they compete at some points and not at others, they produce a discrimination or preference with regard to rates and facilities, which builds up the competitive points at the expense of the non-competitive ones. Such partial competition, with the discrimination it involves, is liable to be worse for the public than no competition at all. It increases the tendency, already too strong, towards concentration of industrial life in large towns. It produces an uncertainty with regard to rates which prevents stability of prices, and is apt to promote the interests of the unscrupulous speculator at the expense of those whose business methods are more conservative. So marked are these evils that such partial competition is avoided by agreements between the competing lines with regard to rates, and by divisions of traffic, or pools, which shall take away the temptation to violate such rate agreements. The common law has been somewhat unfavourable to the enforcement of such agreements, and statutes in the United States, both local and national, have attempted to prohibit them; but the public advantage from their existence has been so great as to render their legal disabilities inoperative. In those parts of the continent of Europe where railways are owned and administered by state authority, the necessity for such agreements is frankly admitted.

But if rates are to be fixed by agreement, and not by competition, what principle can be recognized as a legitimate basis of railway rate-making? The first efforts at railway legislation were governed by the equal mileage principle; that is, the attempt was made to make rates proportionate to the distance. It was, however, soon seen that this was inadmissible. So much of the expense of the handling, both of freight and of passengers, was independent of the length of the journey that a mileage rate sufficiently large for short distances was unnecessarily burdensome for long ones, and was bound to destroy long-distance traffic, if the theory were consistently applied. The system has been retained in large measure in passenger business, but only because of the conflict which inevitably occurs between the authorities and the passengers with regard to the privilege of breaking and resuming a journey when passenger rates are arranged on any other plan. In freight schedules it has been completely abandoned.

A somewhat better theory of rate regulation was then framed, which divided railway expenditures into movement expense, connected with the line in general, and terminal expense, which connected itself with the stations and station service. Under this system each consignment of freight is compelled to pay its share of the terminal expense, independently of distance, plus a mileage charge proportionate to the length of the journey or haul. There has been also a further attempt in England to divide terminal charges into station and service terminals, according to the nature of the work for which compensation is sought. But none of these classifications of expense reaches the root of the matter. A system of charges which compels each piece of traffic to pay its share of the charges for track and for stations overlooks the fundamental fact that a very large part of the expenses of a railway - more than half - is not connected either with the cost of moving traffic or of handling traffic at stations, but with the cost of maintaining the property as a whole. Of this character are the expenditures necessary for maintenance of way, for general administration and for interest on capital borrowed, which are almost independent of the total amount of business done, and quite independent of any individual piece of business. To say that all traffic must bear its share of these interest and maintenance charges is to impose upon the railways a rate which would cut off much of the longdistance traffic, and much of the traffic in cheap articles, which is of great value to the public, and which, from its very magnitude, is a thing that railways could not afford to lose. It is also a fact that with each recurring decade these general expenses (also called indirect, undistributed or fixed charges) have an increased importance as compared with the particular (direct, distributed or operating) expense attaching naturally to the particular portions of the traffic. For with increased density of population it becomes profitable to make improvements on the original location, even though this may involve increased charges for interest and for some parts of its maintenance, for the sake of securing that economy of operation, through larger train-loads, which such an improved location makes possible.

Whatever the ostensible form of a railway tariff, the contribution of the different shipments of freight to these general expenses is determined on the principle of charging what the traffic will bear. Under this principle, rates are reduced where the increase of business which follows such reduction makes the change a profitable one. They are kept relatively high in those cases where the expansion of business which follows a reduction is small, and where such a change is therefore unprofitable. This theory of charging what the traffic will bear is an unpopular one, because it has been misapplied by railway managers and made an excuse for charging what the traffic will not bear. Rightly applied, however, it is the only sound economic principle. It means taxation according to ability - that ability being determined by actual experiment.

In the practical carrying out of this principle, railways divide all articles of freight into classes, the highest of which are charged two or three, or even four times the rates of the lowest. This classification is based partly upon special conditions of service, which make some articles more economical to carry than others (with particular reference to the question whether the goods are offered to the companies in car-loads or in small parcels), but chiefly with regard to the commercial value of the article, and its consequent ability to bear a high charge or a low one. For each of these classes a rate-sheet gives the actual ratecharge per unit of weight between the various stations covered by the tariff. This rate increases as the distance increases, but not in equal proportion; while the rates from large trade centres to other trade centres at a great distance are not higher than those to intermediate points somewhat less remote; if the law permits, there is a tendency to make them actually a little lower. Besides the system of charges thus prescribed in the classification and rate-sheet, each tariff provides for a certain number of special rates or charges made for particular lines of trade in certain localities, independently of their relation to the general system. If these special rates are published in the tariff, and are offered to all persons alike, provided they can fulfil the conditions imposed by the company, they are known as commodity rates, and are apparently a necessity in any scheme of railway charges. If, however, they are not published, and are given to certain persons as individual favours, they become a prolific source of abuse, and are quite indefensible from the standpoint of political economy.

While the superficial appearance of the railway tariff is different for different countries, and sometimes for different parts of the same country, the general principles laid down are followed in rate-making by all well-managed lines, whether state or private. It is a mistake to suppose that the question of public or private ownership will make any considerable difference in the system of rate-making adopted by a good railway. A state system will be compelled, by the exigencies of the public treasury, to arrange its rates to pay interest on its securities; a private company will generally be prevented, by the indirect competition of railways in other parts of the country which it serves, from doing very much more than this. The relative merit of the two systems depends upon the question how we can secure the best efficiency and equity in the application of the principles thus far laid down. There are three different systems of control: I. Private operation, subject only to judicial regulation, was exemplified most fully in the early railway history of the United States. Until 1870 railway companies were almost free from special acts of control; and, in general, any company that could raise or borrow the capital was allowed to build a railway wherever it saw fit. In the United Kingdom there was almost as much immunity from legislative interference with charges, but the companies were compelled to secure special charters, and to conform to regulations made by the Board of Trade in the interests of public safety. The advantage of this relatively free system of railway building and management is that it secures efficient and progressive methods. Most of the improvements in operation and in traffic management have had their origin in one of these two countries. The disadvantage attendant upon this system is that the courts are reluctant to exercise the right of regulation, except on old and traditional lines, and that in the face of new business methods the public may be inadequately protected. There is also this further disadvantage, that in the gradual progress of consolidation railway companies take upon themselves the aspect of large monopolies, of whose apparently unrestricted power the public is jealous. As a result of these difficulties there has been, both in the United Kingdom and in the United States, a progressive increase of legislative interference with railways. In the former the Railway and Canal Traffic Act of 1854 specially prohibited preferences, either in facilities or in rates. The Regulation of Railways Act of 1873 provided for a Railway Commission, which should be so constituted as to take cognizance of cases on the investigation of which the courts were reluctant to enter. Finally, the legislation of 1888 put into the hands of a reorganized Railway Commission and of the Board of Trade powers none the less important in principle because their action has been less in its practical effect than the advocates of active control demanded. In the United States the years from 1870 to 1875 witnessed sweeping and generally ill-considered legislation (" Granger " Acts) concerning railway charges throughout the Mississippi valley; while the years from 1884 to 1887 were marked by more conservative, and for that reason more enforceable, acts, which culminated in the Interstate Commerce Act, prohibiting personal discrimination and gradually restricting discrimination between places, and providing for a National Commission of very considerable power - not to speak of the pooling clause, which was extraneous to the general purpose of the act, and has tended to defeat rather than strengthen its operation.

2. Operation by private companies, under specific provisions of the government authorities with regard to the method of its exercise, has been the policy consistently carried out in France, and less systematically and consistently in other countries under the domination of the Latin race. It was believed by its advocates that this system of prescribing the conditions of construction and operation of lines could promote public safety, prevent waste of capital and secure passengers and shippers against extortionate rates. These expectations have been only partially fulfilled. Well trained as was the civil service of France, the effect of this supervision in deadening activity was sometimes more marked than in its effect in preventing abuse. Moreover, such a system of regulation almost necessarily carries with it a guarantee of monopoly to the various companies concerned, and not infrequently large gifts in the form of subsidies, for without such aid private capital will not submit to the special burdens involved. These rights, whether of monopoly or of subsidy, form a means of abuse in many directions. Where the government is bad, they are a fruitful source of corruption; even where it is good, they enable the companies to drive hard bargains with the public, and prevent. the expected benefits of official control from being realized.

3. State operation and ownership is a system which originated in Belgium at the beginning of railway enterprise, and has been consistently carried out by the Scandinavian countries and by Hungary. Since 1860 it has been the policy of Australia.. It has generally come to be that of Germany and, so far as the finances of the countries allow, of Austria and Russia; British India also affords not a few examples of the same method. The theory of state ownership is excellent. So large a part of the railway charge is of the nature of a tax, that there seem to be a priori reasons for leaving the taxing powers in the hands of the agents of the government. In practice its operation is far more uncertain. Whether the intelligence and efficiency of the officials charged by the state with the handling of its railway system will be sufficient to make them act in the interest of the public as fully as do the managers of private corporations, is a question whose answer can only be determined by actual experience in each case. If they fail to have these qualities, the complete monopoly which a government enjoys, and the powers of borrowing which are furnished by the use of the public credit, increase instead of diminishing the danger of arbitrary action, unprogressiveness and waste of capital. Even in matters like public safety it is by no means certain that government authorities will do so well as private ones. The question is one which practical railway men have long since ceased to argue on general principles; they recognize that the answer depends upon the respective degree of talent and integrity which characterize the business community on the one hand and the government officials on the other.

- On economics of construction and of operation, see Wellington, The Economic Theory of Railway Location (5th ed., New York, 1896). On principles governing railway rates in general, and specifically in England, see Acworth, The Railways and the Traders (London, 1891). On comparative railway legislation and the principles governing it, see Hadley, Railroad Transportation; its History and its Laws (New York, 1885). On the history of railway legislation in England, see Cohn, Untersuchungen fiber die Englische Eisenbahnpolitik (Leipzig, 1874-83). On practice concerning rates in continental Europe, see Ulrich, Des Eisenbahntarifwesen (Berlin, 1886). (Since this was published, continental passenger rates havefallen. The French translation - Paris, 1898 - gives Russian tariffs.) On the question of " nationalization " (i.e. state ownership and operation), see an article by Edgar Crammond in the Quarterly Review (London) for October 1909, which cites, among other works on the subject, Clement Edwards's Railway Nationalization (1898); Edwin A. Pratt's Railway Nationalization (1908), and E. A. Davis's Nationalization of Railways (1908). (A. T. H.) British Railway Legislation The first thing a railway company in Great Britain has to do is to obtain a special or private act of parliament authorizing the construction of the line. Not that the mere laying or working of a railway requires parliamentary sanction, so long as the work does not interfere with other people's rights and interests. An example of a railway built. without any legislative authority is the little mountain railway from Llanberis to the summit of Snowdon, which was made by the owner of the land through which it passes. Such a railway has no statutory rights and no special obligations, and the owner of it is liable to be sued for creating a nuisance if the working of the line interferes with the comfort of those residing in the neighbourhood. When, however, a company desires to construct a line on a commercial scale, to acquire land compulsorily, to divert rivers and streams, to cross roads either on the level or by means of bridges, to pass near houses, to build tunnels or viaducts, and to execute all the other works incidental to a. railway, and to work the line when completed without interference, it is essential that the authority of parliament should be obtained. The company therefore promotes a bill, which is considered first by select committees of the two houses of parliament, and afterwards by the two houses themselves, during which period it faces the opposition, if any, of rival concerns, of local authorities and of hostile landowners. If this is successfully overcome, and the proposals meet with the Con approval of parliament, the bill is passed and, after securing the Royal Assent, becomes an act of parliament. The company is then free to proceed with the work of construction, and at once becomes subject to various general acts, such as the Companies Clauses Act, which affects all joint-stock companies incorporated by any special act; the Land Clauses Act, which has reference to all companies having powers to acquire land compulsorily; the Railway Clauses Act, which imposes certain conditions on all railways alike (except light railways); the various Regulation of Railways Acts; the Carriers Protection Act; acts for the conveyance of mails, parcels, troops; acts relating to telegraphs, to the conveyance of workmen and to the housing of the labouring classes; and several others which it is unnecessary to specify. From the early days of railways parliament has also been careful to provide for the safety of the public by inserting in the general or special acts definite conditions, and by laying upon the Board of Trade the duty of protecting the public using a railway.

The first act which has reference to the safety of passengers is the Regulation of Railways Act of 1842, which obliges every railway company to give notice to the Board of Trade of its intention to open the railway for passenger traffic, and places upon that public department the duty of inspecting the line before the opening of it takes place.. If the officer appointed by the Board of Trade should, after inspection of the railway, report to the department that in his opinion " the opening of the same would be attended with danger to the public using the same, by reason of the incompleteness of the works or permanent way, or the insufficiency of the establishment for working such railway," it is lawful for the department to direct the company to postpone the opening of the line for any period not exceeding one month at a time, the process being repeated from month to month as often as may be necessary. The company is liable to a fine of twenty pounds a day if it should open the line in contravention of such order or direction. The inspections made by the officers of the Board of Trade under this act are very complete: the permanent way, bridges, viaducts, tunnels and other works are carefully examined; all iron or steel girders are tested; stations, including platforms, stairways, waiting-rooms, &c., are inspected; and the signalling and " interlocking " are thoroughly overhauled. A code of requirements in regard to the opening of new railways has been drawn up by the department for the guidance of railway companies, and as the special circumstances of each line are considered on their merits, it rarely happens that the department finds it necessary to prohibit the opening of a new railway. The Regulation of Railways Act of 1871 extends the provisions of the above act to the opening of " any additional line of railway, deviation line, station, junction or crossing on the level " which forms a portion of or is connected with a passenger railway, and which has been constructed subsequently to the inspection of it. This act further defines the duties and powers of the inspectors of the Board of Trade, and also authorizes the Board to dispense with the notice which the previous act requires to be given prior to the opening of a railway.

It' may be remarked that neither of these acts confers on the Board of Trade any power to inspect a railway after it has once been opened, unless and until some addition or alteration, such as is defined in the last-named act, has been made. When a line has once been inspected and passed, it lies with the company to maintain it in accordance with the standard of efficiency it originally possessed, but no express statutory obligation to do so is imposed upon the company, and whether it does so or not, the Board of Trade cannot interfere.

The act of 1871 further renders it obligatory upon every railway company to send notice to the Board of Trade in the case of (1) any accident attended with loss of life or personal injury to any person whatsoever; (2) any collision where one of the trains is a passenger train; (3) any passenger train or part of such train leaving the rails; (4) any other accident likely to have caused loss of life or personal injury, and specified on that ground by any order made from time to time by the Board of Trade. The department is authorized, on receipt of such report, to direct an inquiry to be made into the cause of any accident so reported, and the inspector appointed to make the inquiry is given power to enter any railway premises for the purposes of his inquiry, and to summon any person engaged upon the railway to attend the inquiry as a witness, and to require the production of all books, papers and documents which he considers important for the purpose. The inspector, after making his investigation, is required to make a report to the Board of Trade as to the causes of the accident and the circumstances attending the same, with any observations on the subject which he deems right, and the Board " shall cause every such report to be made public in such manner as they think expedient." The usual mode of publishing such reports is to forward them to railway companies concerned, as well as to the press, and on application to any one else who is interested. The reports are subsequently included in a Blue-book and presented to parliament. It should be noted that although the inspecting officer may in his report make any recommendations that he may think fit with a view to guarding against any similar accident occurring in the future, no power is given to the Board of Trade, or to any other authority, to compel any railway company to adopt such recommendations. This omission is sometimes held to be an error, but as a fact it is an advantage. The moral effect of the report, with the criticisms of the company's methods and recommendations appended thereto, is great, and it rarely happens that a company refuses to adopt, or at any rate to test, the recommendations so made. If, on the other hand, the company is of opinion that the suggestions of the inspecting officer are not likely to prove beneficial, or are for any reason unadvisable, it is at liberty to reject them, the responsibility of doing so resting entirely upon itself. The effect of this latitude is to give the company ample discretion in the matter, and to enable the act to be administered and the object of it to be attained without undue interference.

In 1889 a very important act was passed placing upon the Board of Trade the obligation to call upon railway companies throughout the United Kingdom (1) to adopt upon all passenger lines the " block " system of working; (2) to " interlock " their points and signals; (3) to fit all trains carrying passengers with some form of automatic continuous brake. Prior to this some companies had, to a certain extent, done these things, but few, if any, were completely equipped in these respects. A reasonable period was afforded them, according to circumstances, to comply with these requirements, and at the present time the work is practically complete. In this respect the lines of the United Kingdom are far ahead of those of any other country, and a diminution of accidents, particularly of collisions, has resulted therefrom. America is now following the lead thus set, and all the most important lines in the United States have adopted block working and interlocking, but a great deal still remains to be done. In certain respects, on the other hand, America has gone further than the United Kingdom, especially in the matter of automatic signalling, and in the operating of points and signals by electrical power or air-pressure instead of manual labour. In America, also, freight trains are fitted with an automatic continuous brake, whereas in the United Kingdom this appliance is required by law only in the case of passenger trains, and in fact is not fitted to goods and mineral trains except in a few isolated instances.

The above-named acts enable the Board of Trade to take all the necessary steps to ensure that the safety of passenger trains is sufficiently guarded. More recently legislation has beenassed to safeguard the lives and interests of Hours of P g Lab ur. railway servants. In 1893 an act was passed by parliament giving the Board power to interfere if or when representations are made to them by or on behalf of any servant or class of servants of a railway company that the hours of work are unduly long, or do not provide sufficient intervals of uninterrupted rest between the periods of duty, or sufficient relief in respect of Sunday duty. In such cases the company concerned may, after inquiry, be called upon to submit such a schedule of the hours during which the man or men are employed as will bring those hours within limits which appear to the department reasonable. In the event of the company failing to comply with the demands of the department, the latter is empowered to refer the case to the Railway and Canal Commissioners, who form a special Court constituted by the Railway and Canal Traffic Act of 2888, for deciding, among other things, questions relating to rates and charges, for protecting traders from undue charges and undue preference, for regulating questions of traffic, and for deciding certain disputes between railway companies and the public. The Commissioners are then empowered to deal with the matter, and if " a railway company fail to comply with any order made by the Railway and Canal Commissioners, or to enforce the provisions of any schedule " approved by them, it is liable to a fine of a hundred pounds for every day during which the default continues. This act has been the means of effecting a considerable reduction in the hours worked by railway men on certain railways, and no case has yet arisen in which a reference to the Commissioners has been necessary. Such modifications of the hours of work have not only been beneficial to the men, but have improved the discipline of the staff and the punctuality and regularity of the train service, particularly in respect of the goods trains.

The Notice of Accidents Act of 1884, which obliges employers of labour to report to the Board of Trade, when "there occurs in any employment " as defined by the schedule of the act, " any accident which causes to any person employed therein, either loss of life or such bodily injury as to prevent him on any one of the three working days next after the occurrence of the accident from being employed for five hours on his ordinary work," affects railways in course of construction, but not, as a rule, otherwise. Although the administration of the above-mentioned acts of parliament has had a beneficial effect upon the safety of the public, and has enabled an enormous volume of traffic Safety to be handled with celerity, punctuality and absence Y? P Y of risk, it has during recent years come to notice that the number of casualties among railway servants is still unduly great, and in 1899 a Royal Commission was appointed to investigate the causes of the numerous accidents, fatal and nonfatal, to railway men. As a consequence of the report of this Commission the Railway Employment (Prevention of Accidents) Act of 'goo was passed, putting upon the Board of Trade the duty of making " such rules as they think fit with respect to any of the subjects mentioned in the schedule to this act, with the object of reducing or removing the dangers and risks incidental to railway service." Rules may also be made in respect to other matters besides those mentioned in the schedule, and companies may be called upon to adopt or reject, as the case may be, any appliance, the use or disuse of which may be considered desirable in the interest of the men. Before, however, the rules so made become binding upon the companies, the latter have the right of appealing against them to the Railway Commissioners. Failure to comply with any of the rules renders a company " liable for each offence, on conviction under the Summary Jurisdiction Acts, to a fine not exceeding fifty pounds, or in the case of a continuing offence to a fine not exceeding ten pounds for every day during which the offence continues after conviction." Rules drafted by the Board of Trade under this act came into force on the 8th of August 1902, the subjects referred to being (I) labelling of wagons; (2) movements of wagons by propping and tow-roping; (3) power-brakes on engines; (4) lighting of stations and sidings; (g) protection of points, rods, &c.; (6) construction and protection of gauge-glasses; (7) arrangement of tool-boxes, &c., on engines; (8) provision of brake-vans for trains upon running lines beyond the limits of stations; (9) protection to permanent-way men when relaying or repairing permanent way. The final settlement of a rule requiring brake-levers to be fitted on both sides of goods-wagons was, however, deferred, owing to objections raised by certain of the railway companies.

Other acts which are of importance in connexion with accidents are the Accidents Compensation Act of 1846, the Employers' Liability Act of 1880, and the Workmen's Compensation Act of 1897.

The public acts of parliament referring to British railways are collected in Bigg's General Railway Acts. (H. A. Y.) American Railway Legislation Before 1870. - The earliest legislation is contained in charters granted by special act, for the construction of railways. These special acts gradually gave way to general statutes under which railway corporations could be created without application to the legislature. In the east, where, as a rule, charters had been uniform and consistent, the change to general incorporation law was due to a desire to render incorporations speedier and less expensive. In the west, general laws came rather as a result of the abuses of special legislation. By 1850, general incorporation laws were found in nearly all the eastern states, and by 1870 in those of the west.

Early legislation was confined almost entirely to matters of construction. In cases where statutes did touch the question of regulation, they had to do with the operation of trains and with the provision of facilities for shippers and passengers, rather than with questions of rates. It was natural that this should be so, for the new transportation agency was so much more efficient than anything previously available that the people were eager to take advantage of its superior service. As a rule, the making of rates was left to the corporations. If the maximum rates were prescribed, as they sometimes were, the limit was placed so high as to be of no practical value for control. Such crude attempts as were made to prevent rates from being excessive concerned themselves with profits, and were designed to confiscate for the state treasury any earnings beyond a certain prescribed dividend. Publicity of rates was not generally required, and provisions against discrimination were rare. In the period before 1850 there was but little realization of the public nature of the railway industry and of the possibilities of injury to the public if railway corporations were left uncontrolled.

In regions where capital was lacking eagerness for railway facilities led the people to demand the direct co-operation of the state, and many projects, most of which ended in disaster, were undertaken either by the state itself or through the aid of the state's credit. For example, Michigan, in 1837, in the first session of its state legislature, made plans for the construction of 557 miles of railway under the direct control of the state, and the governor was authorized to issue bonds for the purpose. The unfortunate results of this policy led many of the states, from about 1850, to put constitutional limitations upon the power of their legislatures to lend the state's credit or to involve the state as stockholder in the affairs of any corporation.

As railway building increased in response to traffic needs, and as the consolidation of short lines into continuous systems proceeded, legislation applicable to railways became somewhat broader in scope and more intelligent. About 1850 there began to appear on the statute books laws requiring publicity of rates and the submission of annual reports to the legislature, prescribing limits to corporate indebtedness, and also making provision for safety in operation and for the character and quality of railway service. Consolidation and leasing were commonly permitted in the case of continuous lines, but were regularly prohibited in the case of parallel and competing lines. The practice of pooling seems not to have attracted the attention of the legislature. In general it may be asserted that legislation of this period was ill-considered, haphazard, and on a petty scale. Moreover, it was of little practical importance even within its narrow range, for it does not appear to have been generally enforced.

Railway legislation first assumed importance in connection with the " Granger Movement " in the middle west. There the policy of subsidies for railway building had been carried to a reckless extreme. Roads had been constructed in advance of settlement, and land-seekers had been transported to these frontier sections only to become dependent upon the railways for their very existence. To the unusual temptations thus offered for favouritism and discriminations in rates, the railways generally yielded. This preferential and discriminating policy, combined with other causes which cannot here be discussed, resulted in 'the Granger legislation of. the 'seventies. In the first instance laws were enacted prescribing schedules of maximum freight and passenger rates with stringent penalties against rebates and discriminations. These measures proving unsatisfactory, they were soon superseded by statutes creating railway commissions with varied powers of regulation. The commission method of control was not a new one. Such bodies, established to appraise land for railway purposes, to apportion receipts and expenditures of interstate traffic, and in a general way to supervise railway transportation, had been in existence in New England before 1860, one of the earliest being that of Rhode Island in 1839. In 1869 Massachusetts had instituted a commission of more modern type, which was given only powers of investigation and recommendation, the force of public opinion being relied upon to make its orders effective. Western commissions, the offspring of the Granger movement, were of a more vigorous type. Most of them had power to impose schedules of maximum rates; practically all of them had authority to prescribe rates upon complaint of shippers; and they could all seek the aid of the courts to enforce their decrees. Their power to initiate rates, conferred upon them by their legislatures, was sustained by the Supreme Court of the United States, the Court reserving to itself only the power to decide whether the prescribed rates were reasonable.

But the jurisdiction of the state commissions was, by judicial interpretation, limited to commerce beginning and ending within the limits of the single state. The most important part of railway transportation, that which was interstate in character, was left untouched. It was this impotence of the state commission that furnished the strongest incentive to Congressional action. The result was the passage, in 1887, of the Interstate Commerce Act, which was directed towards the extirpation of illegal and unjust practices in commerce among the states. Its primary purpose was to embody in statutory form the commonlaw principle of equal treatment under like circumstances, and to provide machinery for enforcement. It aimed at the prohibition of discrimination between persons, places and commodities. It made provision for publicity of rates and for due notice of any change in rates; it forbade pooling of freight or earnings, and required annual reports from the carriers. For its enforcement, it created an Interstate Commerce Commission of five members, with powers of investigation, and with authority to issue remedial orders upon complaint and after hearing. Findings of the Commission were to be prima facie evidence in any court proceeding for the enforcement of its orders.

In this connexion, reference should be made to the Anti-Trust Act of 1890, which, by its judicial interpretation, has been held to include railways and to forbid rate agreements between competing carriers.

The act of 1887 remained in force without substantial amendment until 1906, although with constantly diminishing prestige, a result largely due to adverse decisions concerning the powers of the Commission. Ten years after the passage of the law, the court decided that the Commission had no power to prescribe a rate, and that its jurisdiction over rates was confined to a determination of the question whether the rate complained of was unreasonable. The Commission had much difficulty at the beginning in securing the testimony of witnesses, who invoked the Constitution of the United States as a bar against selfincrimination, and the immunity clause of the act had to be amended before testimony could be obtained. The so-called " long-and-short-haul clause," which forbade a greater charge for a long than for a short haul over the same line, if circumstances were substantially similar, was also robbed of all its vitality by court decision. The section requiring annual reports, while it led to the creation of a Bureau of Statistics, did not give the Commission power to compel complete or satisfactory answers to its requests for information. The only element of real strength that the statute acquired during the first twenty years of its history came from the Elkins Act of 1903, which stipulated that the published rate should be the legal rate, and declared any departure from the published rate to be a misdemeanour. It held shipper as well as carrier, and corporation as well as its officer or agent, liable for violations of the act, and conferred upon United States courts power to employ equity processes in putting an end to discrimination. Conviction for granting rebates was by this law made easier and more effective.

The movement in favour of more vigorous railway regulation became pronounced after 1900. Twenty years of experience and observation had revealed the defects of the earlier legislation, and had concentrated public attention more intelligently than ever before upon the problem of strengthening the weak spots. The state commissions, since their establishment in the 'seventies and the 'eighties, had increased their functions and influence. Many of them, beginning only with powers of recommendation, had obtained a large extension of authority. By 1908, thirty-five of the forty state commissions were of the mandatory type, and thirteen of these had been created since 1904. They had been given power to require complete annual reports from carriers, with a consequent great increase in public knowledge concerning railway operation and practice. The most recent type of state commission is the so-called Public Utility Commission, of which the best examples are those of New York and Wisconsin, established in 1907. In both states, the Commissions have power over electric railways and local public utilities furnishing heat, light and power, as well as over steam railway transportation, and the Wisconsin Commission also has control over telephone companies. In both states the consent of the Commission is necessary for the issue of corporate securities.

Mention should be made of the mass of general legislation passed, principally by western states, since 1905, in response to a popular demand for lower rates. This demand has in many instances led to ill-considered legislation, has frequently ignored the prerogatives and even the existence of the state commissions, and has brought about the passage by state legislatures of maximum freight and passenger rate laws, with rates so low in many cases that they have been set aside by the courts as unconstitutional. The numerous laws limiting the fare for passengers to two cents per mile are an illustration of this tendency.

In the field of federal legislation, no significant change took place until the passage of the Hepburn Act of 1906, which was an amendment of the act of 1887. While failing to correct all the defects in the original statute, the amended law was a decided step in the direction of efficient regulation. It increased the jurisdiction of the Commission by placing under the act express companies, sleeping-car companies and pipe lines for the transportation of oil. It extended the meaning of the term " railroad " to include switches, spurs and terminal facilities, and the term " transportation " to include private cars, and all collateral services, such as refrigeration, elevation and storage. The Elkins Act of 1903 was incorporated in the statute, and an imprisonment penalty was added to the existing fine. It forbade the granting of passes except to certain specified classes, - a provision entirely absent from the original measure. It expressly conferred upon the Commission the power to prescribe maximum rates, upon complaint and after hearing, as well as to make joint rates, and to establish through rates when the carriers had themselves refused to do so. It enacted that published rates should not be changed except on thirty days' notice, whether the change involved an increase or a decrease, and it required annual reports to be made under oath, penalties being prescribed for failure to comply with the Commission's requests for information. Power was also given to prescribe uniform systems of accounts for all classes of carriers, and to employ special examiners to inspect the books and accounts. Carriers were forbidden to keep any accounts, records or memoranda other than those approved by the Commission.

Orders of the Commission became effective within such time, not less than thirty days, as the Commission should prescribe, and penalties began to take effect from the date fixed by the Commission, unless the carrier secured an injunction from the Court suspending the order. Such injunction might not issue except after hearing, of which five days' notice must be given. Decisions of the Commission were not reviewable by the Court unless the Commission had exceeded its authority, or had issued an unconstitutional order.

A new and important act was signed by the President on the 18th of June 1910. It created a Commerce Court (composed of five judges nominated by the president of the United States from the Federal circuit judges), transferred to it jurisdiction in cases instituted to enforce or set aside orders of the Inter-State Commerce Commission, and made the United States instead of the Commission a party in all such actions. The law forbids a railway or any other common carrier to charge more for a short haul than for a long haul over the same line, unless, in special cases, it is authorized to do so by the Commission. It forbids a railway which has reduced its rates while in competition with a water route to raise them again when the competition has ceased, unless the Commission permits it to do so because of other changed conditions. It extends the initiative of the Commission from the investigation of complaints to the investigation of rates on its own motion; authorizes it to suspend rates in advance of their going into effect, pending an investigation which may be continued for ten months, and to establish through routes; and provides for a special commission, appointed by the President, to investigate questions pertaining to the issuance of railway securities.

Bibliography. - See A. T. Hadley, Railroad Transportation (New York, 1885); B. H. Meyer, Railway Legislation in the United States (New York, 1903); F. A. Cleveland and F. W. Powell, Railroad Promotion and Capitalization in the United States (New York, 1909); L. H. Haney, A Congressional History of Railways (2 vols., Madison, Wis., 1908 and 1910); Elkins Committee Report (1905); F. H. Dixon, " The Interstate Commerce Act as Amended," Quarterly Journal of Economics, xxi. 22 (Nov. 1906); F. H. Dixon, " Recent Railroad Commission Legislation," Political Science Quarterly, xx. 612 (Dec. 1905). (F. H. D.*) Accident Statistics Statistics of railway accidents may be divided into three classes: casualties (a) to passengers, (b) to servants or employ& and (c) to other persons; and again into (t) train accidents, (2) accidents to persons doing work on or about trains and (3) other accidents.

Such statistics are studied mainly with the object of learning the lessons which they may afford as to preventive measures for the future; and from this point of view the most important element is the single item of passengers killed in train accidents (a 1). The number injured is, indeed, a fact of interest, no less than the number killed, but comparisons under this head are unsatisfactory because it is impracticable or unprofitable to go into sufficient detail to determine the relative seriousness of the injuries. The statistics of the killed usually afford all necessary stimulus to improvement. Accidents to passengers other than those caused by collisions or derailments of trains are very largely due to causes which it is fair to class either as unavoidable or as due mainly to the fault or carelessness of the victim himself. That this is so is indicated by the fact that, although the railways - always made to suffer severely in pecuniary damages for injuries for which their officers or servants are held responsible by the courts - have for years taken almost every conceivable precaution, the number of accidents, in proportion to the number of persons travelling, diminishes but slowly - so slowly that, in view of the variety of conditions to be considered, it would hardly be safe to conclude that the diminution is due to any definite improvement in the safeguards provided. Collisions, on the other hand, are preventable, and derailments nearly so, and the records of deaths and injuries in this class in successive years are therefore justly taken as an index to the efficiency with which the railways are managed.

The number of servants killed in train accidents is the next in importance. The safety of passengers is, indeed, the first care of the railway manager; but the employes, exposed to many risks from which the passengers are protected, must be looked after. On the British railways the men who run the trains are safeguarded very efficiently, and the collisions and derailments which are serious enough to do injury to the trainmen or the enginemen are really rare. The roadway, tracks and rolling stock are so well maintained that those causes which lead to the worst derailments have been eliminated almost completely, and the record of serious collisions has been reduced nearly to zero by the universal use of the block system and by systematic precautions at junctions. In America the record is far less satisfactory. The best railways of the United States and Canada have, indeed; been greatly improved, and their main lines approach the high standards of safety which prevail in Great Britain, both as regards maintenance and care of roadway and vehicles (as a preventive of derailments) and the use of the block system (as a preventive of collisions); but when the inquirer looks at America as a whole - the total length of lines in the United States being over 230,000 m., ten times the total of the United Kingdom - he is considering a figure which includes an enormous mileage of railway lying in thinly settled regions where the high standards of safety maintained on the best railways have scarcely been thought of. The duty of a railway with deficient plant or facilities would seem to be to make up for their absence by moderating the speeds of its trains, but public sentiment in America appears so far to have approved, at least tacitly, the combination of imperfect railways and high speeds.

Apart from collisions and derailments, a large proportion of all accidents is found to be due primarily to want of care on the part of the victims. Accidents to workmen in marshalling, shunting, distributing and running trains, engines and cars, may be taken as the most important class, after train accidents, because this work is necessary and important and yet involves considerable hazard. On British railways the duty of the companies to provide all practicable safeguards and to educate and caution the servants may be said to have been faithfully performed, and the accident totals must be taken as being somewhat near the " irreducible minimum" - unless some of the infirmities of the human mind can be cured. In America the number of men killed and injured in handling freight trains has been very large. In the year ending June 30, 1909, exclusive of casualties due to collisions, derailments and other accidents to trains, the number killed was 811 and of injured 28,156 (Accident Bulletin, No. 32, p. 14). The number killed (811) is equal to about three in every thousand trainmen employed. From this and all other causes, the number of trainmen killed in the year ending June 30, 1909, was about 8 in t000.

The use of automatic couplers for freight cars throughout the United States, introduced in 1893-1900, greatly reduced the number of deaths and injuries in coupling, and the use of air brakes on freight cars, now universal, has reduced the risk to the men by making it less necessary for them to ride on the roofs of high box-cars, while at the same time it has made it possible to run long trains with fewer men; but except in these two features the freight service in America continues to be a dangerous occupation. The high and heavy cars, the high speeds, the severe weather in the northern states in winter, the fluctuating nature of the business, resulting often in the employment of poorly qualified men and in other irregularities, are among the causes of this state of things.

Being struck or run over by a train while standing or walking on the track is the largest single cause of " railway accidents." Workmen are killed and injured in this way, both while on duty and when going to and from their work; passengers, with or without right, go in front of trains at stations and at highway crossings at grade level; and trespassers are killed and injured in large numbers on railways everywhere, at and near stations, at crossings, and out on the open road, where they have no shadow of right. Of trespassers the number killed per mile of line is about as large in England as in America, the density of population and of traffic in Great Britain apparently counterbalancing the laxity of the laws against trespassing in America. In the thickly settled parts of the United States the number of trespassers killed on the railway tracks, including vagrants who suffer in collisions and derailments while stealing rides, is very large. In New York and four adjacent states, having about as many miles of railway as the United Kingdom, the number in the year ending June 30, 1907, was 1552. In the United Kingdom the number for the corresponding year was 447, or less than one-third.

As was suggested at the outset, railway accident statistics are useful only as showing how to make life and limb safer, though in pursuing this object increased economy should also be secured. Railways have always been held by the legislatures and by the courts strictly accountable for their shortcomings, so far as accountability can be enforced by compelling the payment of damages to victims of accidents; but in spite of this, a want of enterprise and even some apparent neglect of passengers' and servants' plain rights, have often been apparent, and the Board of Trade, with its powers of supervision, inspection and investigation, must therefore be classed as one of the most beneficent factors in the promotion of safety on British railways. Its powers have been exercised with the greatest caution, yet with consistent firmness; and the publicity which has been given to the true and detailed causes of scores and scores of railway accidents by the admirable reports of the Board of Trade inspectors has been a powerful lever in improving the railway service. Useful compulsory laws regarding the details of train management are difficult to frame and hard to carry out; but the Board has exercised a persistent persuasiveness and has secured most of its objects. Its investigations justified the law making the block system compulsory, thus removing the worst danger of railway travel. Its constant and impartial expositions of cases of over-work and insufficient training of employes have greatly helped to elevate the character of these employes. In the United States the governments have done far less.

A majority of the states have railway commissions, but the investigation of railway accidents, with comparatively few exceptions, has not been done in such a way as to make the results useful in promoting improved practice. Many of the commissions have done little or nothing of value in this respect. The Federal government, having authority in railway matters only when interstate traffic is affected, gathers statistics and publishes them; but in the airing of causes-the field in which the British Board of Trade has been so useful-nothing so far has been done except to require written reports monthly from the railways. These are useful so far as they go, but they lack the impartiality that would be secured by an inquiry such as is held in England.

Table X.-Casualties On The Railways Of The United Kingdom 1908.1907.In Passengers:- Billed. j u ed. Killed. j u ed.

i. In train accidents. 0 283 18 534 2. Other accidents in or around trains, &c. 102 2,242 102 2,132 3. Other causes 5 863 5 836 Total of passengers 107 3,388 125 3,502 Servants:- II. On business at stations 32 580 12. Miscellaneous. 27 167 Total of " other persons ". 5899 16 Grand total. 1,128 28,485 1,211 25,975 The casualties enumerated in items I, 4 and 7 of Table X. aggregate 6 killed and 454 injured; the six deaths were due to collisions, while of the cases of injury 372 occurred by collisions, 47 by derailments, and 35 by other accidents to trains. This undoubtedly is the greatest record for train safety ever known in the world. Item I shows no passengers killed in train accidents during the year. This was the case once before, in 1901; and the total of fatal accidents to passengers and servants, taken together, has in several years been very low (1896, eight; 1901, eight; 1902, ten; 1904, thirteen), but never before was it down to six.

Items 2 and 5 in Table X. are made up of the classes of accidents shown in Table XI.

Table Xi.-Detail Causes Of Certain Accidents Year 1908. Killed. Injured.

(a) When entering trains.. 21 53 (b) When alighting from trains. 2 110 2. From falling on to the platform, ballast, &c.: - (a) When entering trains. .

(b) When alighting from train 3. From falling off platforms and being struck or run over by trains .

4. While crossing the line at stations (a) Where there is either a subway or footbridge. .

(b) Where there is neither a subway nor footbridge. .

5. By the closing of carriage doors. .

6. From falling out of carriages during the running of trains .

7. By other accidents Item By accidents occurring during shunting operations, viz. 2. By coming in contact, while riding on i. While coupling or uncoupling vehicles.. 16 675 5, Servants:- Total of passengers. 102 2242 vehicles, with other vehicles, &c., standing on adjacent lines 2 19 3. While passing over, under, or standing on buffers.. 2 13 4. When getting on or off, or falling off engines, wagons, &c.. 4 278 5. While braking, spragging, or chocking wheels 15 627 6. While attending to ground-points.. I 98 7. While moving vehicles by capstans, turn tables, props, levers, &c... 16 498 8. By other accidents not included in the preceding. 41 587 9. From falling off trains, engines, &c., in motion io. When getting on or off engines, vans, &c., during the running of trains. ... 2 226 I i. By coming in contact with over-bridges or erections on the sides of the line 12. While attending to the machinery, &c., of " engines in motion. 2 674 13. While working on the permanent-way, sidings, 14. While attending to gates at level-crossings .

15. While walking, crossing or standing on the line on duty (a) At stations. .. 84 245 (b) At other parts of the line. 40 46 _ 16. From being caught between vehicles.. 23 95 17 From falling, or being caught between trains and platforms, walls, &c.. 10 70 34 31' 18 'While walking, &c., along the line to or from work 19, Miscellaneous. 1 9 595 Total of servants. 376 4976 Table XII. analyses the classes of accident comprised in items, 3 and 6 of Table X.

Table Xii.-Detail'Causes Of Certain Accidents Passengers:- a. While ascending or descending steps at stations .

b. By being struck by barrows, by falling over packages, &c., on station platforms .

13 236 44 1 5,577 55 15,701 509 21,514 5 II 50 30 278 115 169 18 Item 2, Passengers:- I. From falling between trains and platforms 5 43 5 53 52 100331908.1907. Billed. j u ed. Killed. jue 3 3705339' '142 122 ' Servants:- I. While loading, unloading or sheeting wagons, trucks and horseboxes 8 2. While moving goods and luggage in stations or sheds 2 1,992 3. While working at cranes or capstans 3 411 4. By the falling of wagon-doors, lamps, bales of goods, &c.. -. i 583 5. While attending to engines at rest 4 2,479 6. From falling off, or when getting on or off, engines or vehicles at rest 3 1,504 7. From falling off, or when getting on or off, platforms.. I 483 8. From falling off ladders, scaffolds, &c. I I 449 9. By stumbling while walking on the line. 2 1,068 io. By being trampled on or kicked by horses while engaged in rail way work I I I. From being struck by articles thrown from passing trains 12. From the falling of rails, sleepers, &c., when at work on the line .

13. Otherwise injured when at work on the line or in sidings.. 5 2,182 14. Miscellaneous. .. 9 3,085 Total of servants. 50 19,041 (A) Accidents to trains: I. Collisions between passenger trains or parts of passenger trains. .

2. Collisions between passenger trains and goods or mineral trains or light-engines .

3. Collisions between goods trains or parts of goods trains and light-engines .

4. Collisions between trains and vehicles standing foul of the line .

5. Collisions between trains and buffer-stops or vehicles standing against bufferstops: (a) From trains running into stations or sidings at too high a speed. .

(b) From other causes .

6. Trains coming in contact with projections from other trains or vehicles on parallel lines 7. Passenger trains or parts of passenger trains leaving the rails 8. Goods trains or parts of goods trains, lightengines, &c., leaving the rails 9. Trains running through gates at levelcrossings or into other obstacles 10. Fires in trains. .. .

II. Miscellaneous (B) Accidents to or failure of rolling stock and permanent-way: 12. Bursting of boilers or tubes, &c., of engines 13. Failure of machinery, springs, &c., of engines 14. Failure of tires.

15. „ wheels 16. axles. .

17. „ couplings.. .

18. ropes used in working inclines 19. tunnels, bridges, viaducts, culverts, &c. .

20. Broken rails .

21. Flooding of portions of permanent-way 24 22. Slips in cuttings or embankments18 23. Fires at stations or involving injury to. bridges or viaducts. 30 Miscellaneous

I Percentages.-On British railways the casualties from train accidents, especially fatal injuries, have been reduced to so small a proportion of the number of passengers travelling, or the number of servants employed, that the figures showing the percentages vary from year to year considerably; but in other classes of accidents, in which a large proportion of the cases may be classed as unpreventable, the percentages do not vary greatly. The following are the more significant ratios in the year 1907, as shown in the Board of Trade returns: (a) Passengers killed in train accidents, approximately. .. .. i in 83,000,000 (1908, o in 1,500,000,000.) (b) Passengers injured in train accidents, approximately. .. .. I in 3,000,000 (1908, approximately I in 6,000,000.) (c) Servants killed in train accidents Number of servants killed per io,000,000 train miles. .. 0.329 Engine drivers, ratio killed to number employed.. I in 5,628 Firemen, ratio killed to number employed. i in 12,857 Passenger guards, ratio killed to number employed. .. ... I in 4,237 Goods guards and brakemen, ratio killed to number employed.. I in 8,438 (d) Servants killed in work about trains, &c. (excluding train accidents), ratio killed to number employed.. I in 790 Goods guards and brakemen, ratio killed to number employed. I in 409 Shunters, ratio killed to number employed 1 in Engine drivers, ratio killed to number employed. .. I in 1,126 Passenger guards, ra tio killed to number employed. I in 1,059 Railway Accidents in America.-T he statistics of accidents in America are kept in a form somewhat different from the foregoing. Table XIV. is taken from the Accident Bulletin of the Interstate Commerce Commission (No. 32), the items being numbered to correspond as nearly as practicable with the numbers in the British table (No. X.). The items 7-8 embrace the statistics which most nearly correspond to the items 7-12 in the British table.

Table Xiv. -Casualties On The Railways Of The United States Of America Year ending June 30.

1909.1908.

Killed. Injured. Killed. Injured. Passengers:- I. In train accidents. 131 5,865 165 7,430 2, 3. Other causes 204 6,251 241 5,215 Total of passengers. 335 12,116 406 12,645 Servants:- 4. In train accidents.. 520 4,877 642 6,818 5, 6. Other causes 1 ,93646 ,9272 ,7 16 49,526 Total of servants. 2,456 51,804 3,358 56,344 Year ending June 30, 1907.

Other Persons:- Killed. Injured. Killed. Injured.

Trespassing. Not Trespassing. Killed. Injured. Total.

7. In train accidents 97 171 52 1202 1 49 1373 8. Struck by trains at highway cross ings.. 2 37 2 74696 1523 933 1797 Do. at stations. 421423 89259 510 682 Do. at other places.. 373 2 2063 113 200 3845 2263 Other causes. 1125 2581 94 1287 1219 3868 The salient feature of Table XIV. is the diminution from 1908 to 1909. This is mainly due to a great falling off in traffic, because of a general business depression; from 1907 to 1909 the reduction in the accident record is still greater. In items I and 4 the increase in safety is due in part, no doubt, to the extension of the use of the block system. The accidents to " other persons " cannot readily be compared with items 7-12 in the British record, except as to the totals and a few of the items.

In any comparison between British and American records the first point to be borne in mind is the difference in mileage and traffic. The American railways aggregate approximately ten times the length of the British lines; but in train miles the difference is far less. In the latest years in which comparisons can be made, the passenger journeys in the United Kingdom amounted to 1500 millions (including season-ticket holders, estimated) and the train n iles to 428.3 millions, while the corresponding figures in the United States were 873.9 millions and 1171.9 millions. The average length Table Xii.-Detail Causes Of Certain Accidents -continued. 1908. Injured.

Total of passengers 1907.

Killed. Injured.

Killed.

c. From falling off platforms upon the ballast .

d. By other accidents I I 246 .. 5 86 3 5 265 836 4,018 5 2,899 94 7 686 I 5 1,981142,753 55 15,701 2 975 8 304 2 1,495 2 404 II I 1, 0 9 71 6 Table Xiii.-Nature Of Accidents To Trains, Vehicles And Permanent-Way 1908.1907.

United United Kingdom. Kingdom.

43 487870 180 216 7 22 20 17 15 25407 4483 368 364 195 170347 13 61 2 165 287 3 86 172 8 160 2,440 289 40 28 22 337 of the passenger's journey in the United States is reported to be about 32 m.; in Great Britain it is undoubtedly less, but no record is published. Of the total train mileage in America more than half is freight; in Great Britain much more than half is passenger.

[[Table Xv.-Total Casualties On Railways Of The United States]] Total. 10,313 105,234 11,839 '11,016 Table XV. shows the casualties on American railways in 1907 and 1908 (year ending June 30). These figures differ from those in Table XIV. because of differences in classification. In Table XIV. the item " passengers killed " includes those on some electric railways, which presumably are not covered in the statement here given; also passengers in freight trains, &c. Under `' employees " this table includes men in shops, &c., not shown in Table XIV.

In 1907 one passenger in 2,318,051 was killed, and one in 107,004 was injured, in train accidents. The number of employes killed in train accidents was 12.9 in 10 million train miles. Of train men (including engine-drivers and firemen), one out of 125 employed was killed (all causes), and one in eight injured.

The great differences between the records of the United States and the United Kingdom seem to afford justification for the view, which has often been expressed, that in America the spirit of hurry and recklessness manifest in many of the activities of the people prevails even among the men on whom rests the grave responsibility of running trains in safety. Yet the best safety devices are made in America, and means of reducing these death records are well known.

Railway accidents in France are recorded in a shape somewhat different from that found in either Great Britain or America. The principal items for the years 1906 and 1907 are shown in Table XVI. The length of railways in the republic was 39,963 km. (24,832 m.), the number of persons employed on them was rather less than 300,000, the number of passengers carried annually being between 450 and 500 millions. The number of passengers (36) killed in train accidents in 1907 was equal to o0759 per million passengers carried and oo024 per million kilometres travelled by passengers, or 0.1503 per million kilometres travelled by trains.

Table Xvi.-Railway Casualties In France 1907.1906.

Killed. Injured. Killed. Injured. Passengers Servants Other accidents, due to railway operations Passengers and others Servants Other accidents, victim's own fault - Passengers and others. Servants.. .

576 1254 The most significant item in the table, 36 passengers killed in train accidents, is perhaps to be considered as abnormally large, the totals under this head for the preceding six years beginning with 1901 being 7, 35, 3, 18, 4, 14, or an average of 11.57 per year. The French secretary of Public Works, who has furnished these statistics, keeps also similar records of the local or light railways, on which the number of fatal accidents appears to be exceedingly small.

The number of persons killed on the railways of the German Empire in the year 1907 was 1249, classified as in Table XVII. This number does not include suicides and attempts at suicide, of which there were 333, all but 24 being successful. In these statistics, the third item, " other persons," includes post office and customs officials and other persons connected with the railway service, as well as railway officers and servants off duty. The totals of passengers killed and injured in train accidents are not separated from those killed and injured from other causes, but ratios are given showing that for four years no passengers were killed in this class.

Table Xvii.-Railway Casualties In The German Empire (From Statistic der im Betriebe befindlichen Eisenbahnen; E. S. Mittler & Son, Berlin) 1907.1906.

Killed. Injured. Killed. Injured.

1249 2691 1181 2483 See the Quarterly and Annual Reports, issued by the Board of Trade, London, and the Annual Statistical Reports and Quarterly Accident Bulletins, published by the Interstate Commerce Commission, Washington. (B. B. A.) Financial Organization The methods of financing railway enterprises, both new projects and existing lines, have been influenced very largely by the attitude of the state and of municipal authorities. Railways may be built for military reasons or for commercial reasons, or for a combination of the two. The Trans-Siberian railway was a military necessity if Russia was to exercise dominion throughout Siberia and maintain a port on the Yellow Sea or the Sea of Japan. The Union Pacific railroad was a military necessity to the United States if the authority of the national government was to be maintained in the Far West. The cost of such ventures and the detailed methods by which they are financed are of relatively small importance, because they are not required to earn a money return on the investment. To a less degree, the same is true of railways built for a special instead of a general commercial interest. The Baltimore & Ohio railroad was built to protect and further the commercial interests of the city of Baltimore; the Cincinnati Southern railway is still owned by the city of Cincinnati, which built the line in the 'seventies for commercial protection against Louisville, Ky. From a commercial point of view such ventures are differentiated from railway projects built for general commercial reasons because they do not depend on their own credit. The government, national or local, furnishes the borrowing power, and makes the best bargain it can with the men it designates to operate the line.

Where a railway is built for general commercial reasons, however, it must furnish its own credit; that is to say, it must convince investors that it can be worked profitably and give them an assured return on the funds they advance. The state is interested in the commercial railway venture as a matter of public policy, and because it can confer or withold the right of eminent domain, without which the railway builder would be subjected to endless annoyance and expense. This governmental sanction has been obtainable only with difficulty, and after the exercise of numerous legal forms, in Great Britain and on the continent of Europe. In the United States, on the other hand, it has been obtained with considerable ease. In the earlier years of American railway building, each project was commonly the subject of a special law; then special laws were in turn succeeded by general railway laws in the several states, and these in turn have come to be succeeded in most parts of the country by jurisdiction vested in the' state railway commission. Each of these changes has tended to improve the existing status, to legitimize railway enterprise, and to safeguard capital or investment.

The laws regulating original outputs for capital were strictly drawn in Great Britain and on the continent of Europe; in America they were drawn very loosely. As a result it has been far easier for the American than for the European railway builder to take advantage of the speculative instinct in obtaining money. Instead of the borrowing power being restricted to a small percentage of the total capital, as in European countries, most of the railway mileage of America has been built with borrowed money, represented by bonds, while stock has been given freely as an inducement to subscribe to the bonds on the XXII. 2 7 Passengers Servants.. Other persons .

Grand total .

500 132 632 29 17 46 1 55 421 theory that the bonds represented the cost of the enterprise, and the stock the prospective profits. As a natural result weak railway companies in the United States have frequently been declared insolvent by the courts, owing to their inability in periods of commercial depression to meet their acknowledged obligations, and in the reorganization which has followed the shareholders have usually had to accept a loss, temporary or permanent.

The situation in Great Britain has been wholly different. The debt in that country is relatively small in amount, and is not represented by securities based upon hypothecation of the company's real property, as with the American railway bond, resting on a first, second or third mortgage. But British share capital has been issued so freely for extension and is ?- provement work of all sorts, including the costly requirements of the Board of Trade, that a situation has been reached where the return on the outstanding securities tends to diminish year by year. Although this fact will not in itself make the companies liable to any process of reorganization similar to that following insolvency and foreclosure of the American railway, it is probable that reorganization of some sort must nevertheless take place in Great Britain, and it may well be questioned whether the position of the transportation system of that country would not have been better if it had been built up and projected on the experience gained by actual earlier losses, as in the United States.

Thus the characteristic defect in the British railway organization has been the tendency to put out new capital at a rate faster than has been warranted by the annual increases in earnings. The American railways do not have to face this situation; but, after a long term of years, when they were allowed to do much as they pleased, they have now been brought sharply to book by almost every form of constituted authority to be found in the states, and they are suffering from increased taxation, from direct service requirements, and from a general tendency on the part of regulating authorities to reduce rates and to make it impossible to increase them. Meantime, the purchasing power of the dollar which the railway company receives for a specified service is gradually growing smaller, owing to the general increases year by year in wages and in the cost of material. The railways are prospering because they are managed with great skill and are doing increasing amounts of business, though at lessening unit profits. But there is danger of their reaching the point where there is little or no margin between unit costs of service and unit receipts for the service. It will probably be inevitable for American railway rates to trend somewhat upward in the future, as they have gradually declined in the past; but the process apparently cannot be accomplished without considerable friction with the governing authorities. The attitude of the courts is not that the railways should work without compensation, but that the compensation should not exceed a fair return on funds actually expended by the railway. This is in line with the provisions in the Constitution of the United States regarding the protection of property, but the difficulty in applying the principle to the railway situation lies in the fact that costs have to be met by averaging the returns on the total amount cf business done, and it is often impossible, in specific instances, to secure a rate which can be considered to yield a fair return on the specific service rendered. Hence losses in one quarter must be compensated by gains in another - a process which the law, regarding only the gains, renders very difficult.

The growth of railways has been accompanied by a world-wide tendency toward the consolidation of small independent ventures into large groups of lines able to aid one another in the exchange of traffic and to effect economies in administration and in tl-_e purchase of supplies. Both in England and in America this process of consolidation has been obstructed by all known legislative devices, because of the widespread belief that competition in the field of transportation was necessary if fair prices were to be charged for the service. But the general tendency to regulate rates by authority of the state has apparently rendered unnecessary the old plan of rate regulation through competition, even if it had not been demonstrated often and again that this form of regulation is costly for all concerned and is effective only during rare periods of direct conflict between companies. IN evertheless, in spite of difficulties, consolidation -has gone on with great rapidity. When Mr E. H. Harriman died he exercised direct authority over more than 50,000 m. of railway, and the tendency of all the great American railway systems, even when not tied to one another in common ownership, is to increase their mileage year by year by acquiring tributary lines. The smaller company exchanges its stock for stock of the larger system on an agreed basis, or sells it outright, and the bondholders of the absorbed line often have a similar opportunity to exchange their securities for obligations cf the parent company, which are on a stronger basis or have a broader market. Similarly in Great Britain there is a tendency towards combination by mutual agreement among the companies while they still preserve their independent existence.

Table XVIII. shows the paid-up capital, gross receipts, net receipts and proportion of net receipts to total paid-up capital on tile railways of the United Kingdom for a series of years.

Table Xviii. - British Railways A similar comparison (Table XIX.) can be made for the United States of America, statistics prior to the establishment of the Interstate Commerce Commission being taken from Poor's Manual of Railroads as transcribed in government reports.

Table Xix. - American Railways * Includes $ 1 45,3 21, 601 assigned to other than railway property, hut earning net receipts.

j' After taxes; to compare with British figures.

j: This figure should be received with caution. The Interstate Commerce Commission made certain accounting changes this year.

(R. Mo.) Construction Location. - An ideal line of railway connecting two terminal. points would be perfectly level and perfectly straight, because in that case the resistance due to gradients and curves would be eliminated (see § Locomotive Power) and the cost of mechanical operation reduced to a minimum. But that ideal is rarely if ever attainable. In the first place the route of a railway must be governed by commercial considerations. Unless it be quite short, it can scarcely ever be planned simply to connect its two terminal points, without regard to the intervening country; in order to be of the greatest utility and to secure the greatest. revenue it must be laid out with due consideration of the traffic.

arising at intermediate places, and as these will not usually lie exactl y on the direct line, deviations from straightness will be rendered necessary. In the second place, except in the unlikely event of all the places on the selected route lying at the same elevation, a line that is perfectly level is a physical impossibility; and from engineering considerations, even one with uniform gradients will be impracticable on the score of cost, unless the surface of the country is extraordinarily even. In these circumstances the constructor has two broad alternatives between which to choose. On the one hand he may make the line follow the natural inequalities of the ground as nearly as may be, avoiding the elevations and depressions by curves; or on the other he may aim at making it as nearly straight and level as possible by taking it through the elevations in cuttings or tunnels and across the depressions on embankments or bridges. He will incline to the first of these alternatives when cheapness of first cost is a desideratum, but, except in unusually favourable circumstances, the resulting line, being full of sharp curves and severe gradients, will be unsuited for fast running and will be unable to accommodate heavy traffic economically. If, however, cost within reasonable limits is a secondary consideration and the intention is to build a line adapted for express trains and for the carriage of the largest volume of traffic with speed and economy, he will lean towards the second. In practice every line is a compromise between these two extremes, arrived at by carefully balancing a large number of varying factors. Other things being equal, that route is best which will serve the district most conveniently and secure the highest revenue; and the most favourable combination of curves and gradients is that by which the annual cost of conveying the traffic which the line will be called on to carry, added to the annual interest on the capital expended in construction, will be made a minimum.

A cutting, or cut, is simply a trench dug in a hill or piece of rising ground, wide enough at the bottom to accommodate one or more pairs of rails, and deep enough to enable the line to continue its course on the level or on a moderate gradient. The slopes of the sides vary according to the nature of the ground, the amount of moisture present, &c. In solid rock they may be vertical; in gravel, sand or common earth they must, to prevent slipping, rise r ft. for i to r2 or 2 ft. of base, or even more in treacherous clay. In soft material the excavation may be performed by mechanical excavators or " steam navvies," while in hard it may be necessary to resort to blasting. Except in hard rock, the top width of a cutting, and therefore the amount of material to be excavated, increases rapidly with the depth; hence if a cutting exceeds a certain depth, which varies with the particular circumstances, it may be more economical, instead of forming the sides at the slope at which the material of which they are composed will stand, to make them nearly vertical and support the soil with a retaining wall, or to bore a tunnel. An embankment-bank, or fill, is the reverse of a cutting, being an artificial mound of earth on which the railway is taken across depressions in the surface of the ground. An endeavour is made so to plan the works of a railway that the quantity of earth excavated in cuttings shall be equal to the quantity required for the embankments; but this is not always practicable, and it is sometimes advantageous to obtain the earth from some source close to the embankment rather than incur the expense of hauling it from a distant cutting. As embankments have to support the weight of heavy trains, they must be uniformly firm and well drained, and before the line is fully opened for traffic they must be allowed time to consolidate, a process which is helped by running construction or mineral trains over them.

An interesting case of embankment and cutting in combination was involved in crossing Chat Moss on the Liverpool & Manchester railway. The moss was 41 rn. across, and it varied in depth from ro to 30 ft. Its general character was such that cattle could not stand on it, and a piece of iron would sink in it. The subsoil was composed principally of clay and sand, and the railway had to be carried over the moss on the level, requiring cutting, and embanking for upwards of 4 m. In forming 277,000 cub. yds. of embankment 670,000 yds. of raw peat were consumed, the difference being occasioned by the squeezing out of the water. Large quantities of embanking were sunk in the moss, and, when the engineer, George Stephenson, after a month's vigorous operations, had made up his estimates, the apparent work done was sometimes less than at the beginning of the month. The railway ultimately was made to float on the bog. Where embankment was required drains about 5 yds. apart were cut, and when the moss between them was dry it was used to form the embankment. Where the way was formed on the level, drains were cut on each side of the intended line, and were intersected here and there by cross drains, by which the upper part of the moss was rendered dry and firm. On this surface hurdles were placed, 4 ft. broad and 9 long, covered with heath, upon which the ballast was laid.

For conveying small streams through embankments, channels or culverts are constructed in brickwork or masonry. Larger rivers, canals, roads, other railways and sometimes deep narrow valleys are crossed by bridges (q.v.) of timber, brick, stone, wrought iron or steel, and many of these structures rank among the largest engineering works in the world. Sometimes also a viaduct consisting of a series of arches is preferred to an embankment when the line has to be taken over a piece of fiat alluvial plain, or when it is desired to economize space and to carry the line at a sufficient height to clear the streets, as in the case of various railways entering London and other large towns. In connexion with a railway many bridges have also to be constructed to carry public roads and other railways over the line, and for the use of owners or tenants whose land it has cut through (" accommodation bridges "). In the early days of railways, roads were often taken across the line on the level, but such " level " or " grade " crossings are now usually avoided in the case of new lines in populous countries, except when the traffic on both the road and the railway is very light. In many instances old level crossings have been replaced by over-bridges with long sloping approaches; in this way considerable expenditure has been involved, justified, however, by the removal of a danger to the public and of interruptions to the traffic on both the roads and the railways. In cases where the route of a line runs across a river or other piece of water so wide that the construction of a bridge is either impossible or would be more costly than is warranted by the volume of traffic, the expedient is sometimes adopted of carrying the wagons and carriages across bodily with their loads on train ferries, so as to avoid the inconvenience and delay of transshipment. Such train ferries arc common in America, especially on the Great Lakes, and exist at several places in Europe, as in the Baltic between Denmark and Sweden and Denmark and Germany, and across the Straits of Messina.

The gradient or grade of a line is the rate at which it rises or falls, above or below the horizontal, and is expressed by stating either the horizontal distance in which the change of level amounts to r ft., or the amount of change that would occur in some selected distance, such as roo ft., r000 ft. or r m. In America a gradient of r in roo is often known as a r % grade, one of 2 in roo as a 2% grade, and so on; thus a 0-25% grade corresponds to what in England would be known as a gradient of r in 400. The ruling gradient of a section of railway is the steepest incline in that section, and is so called because it governs or rules the maximum load that can be placed behind an engine working over that portion of line. Sometimes, however, a sharp incline occurring on an otherwise easy line is not reckoned as the ruling gradient, trains heavier than could be drawn up it by a single engine being helped by an assistant or " bank " engine; sometimes also " momentum " or " velocity " grades, steeper than the ruling gradient, are permitted for short distances in cases where a train can approach at full speed and thus surmount them by the aid of its momentum. An incline of r in 400 is reckoned easy, of r in 200 moderate and of r in roo heavy. The ruling gradient of the Liverpool & Manchester railway was fixed at r in coo, excepting the inclines at Liverpool and at Rainhill summit, for working which special provision was made; and I. K. Brunel laid out the Great Western for a long distance out of London with a ruling gradient of i in 1320. Other engineers, however, such as Joseph Locke, cheapened the cost of construction by admitting long slopes of i in 80 or 70. One of the steepest gradients in England on an important line is the Lickey incline at Bromsgrove, on the Midland railway between Birmingham and Gloucester, where the slope is 1 in 37 for two miles. The maximum gradient possible depends on climatic conditions, a dry climate being the most favourable. The theoretical limit is about i in 16; between I in 20 and 1 in 16 a steam locomotive depending on the adhesion between its wheels and the rails can only haul about its own weight. In practice the gradient should not exceed i in 221, and even that is too steep, since theoretical conditions cannot always be realized; a wet rail will reduce the adhesion, and the gradients must be such that some paying load can be hauled in all weathers. When an engineer has to construct a railway up a hill having a still steeper slope, he must secure practicable gradients by laying out the line in ascending spirals, if necessary tunnelling into the hill, as on the St Gothard railway, or in a series of zigzags, or he must resort to a rack or a cable railway.

In rack railways a cog-wheel on the engine engages in a toothed rack which forms part of the permanent way. The earliest arrangement of this kind was patented by John Blenkinsop, of the Middleton Colliery, near Leeds, in 1811, and an engine built on his plan by Mathew Murray, also of Leeds, began in 1812 to haul coals from Middleton to Leeds over a line 32 m. long. Blenkinsop placed the teeth on the outer side of one of the running rails, and his reason for adopting a rack was the belief that an engine with smooth wheels running on smooth rails would not have sufficient adhesion to draw the load required. It was not till more than half a century later that an American, Sylvester Marsh, employed the rack system for the purpose of enabling trains to surmount steep slopes on the Mount Washington railway, where the maximum gradient was nearly 1 in 22. In this case the rack had pin teeth carried in a pair of angle bars. The subsequent development of rack railways is especially associated with a Swiss engineer, Nicholas Riggenbach, and his pupil Roman Abt, and the forms of rack introduced by them are those most commonly used. That of the latter is multiple, several rack-plates being placed parallel to each other, and the teeth break joint at 1, a or 4 of their pitch, according to the number of rack-plates. In this way smoothness of working is ensured, the cog-wheel being constantly in action with the rack. Abt also developed the plan of combining rack and adhesional working, the engine working by adhesion alone on the gentler slopes but by both adhesion and the rack on the steeper ones. On such lines the beginning of a rack section is provided with a piece of rack mounted on springs, so that the pinions of the engine engage smoothly with the teeth. Racks of this type usually become impracticable for gradients steeper than 1 in 4, partly because of the excessive weight of the engine required and partly because of the tendency of the cog-wheel to mount the rack. The Locher rack, employed on the Mount Pilatus railway, where the steepest gradient is nearly I in 2, is double, with vertical teeth on each side, while in the Strub rack, used on the Jungfrau line, the teeth are cut in the head of a rail of the ordinary Vignoles type.

For surmounting still steeper slopes, cable railways may be employed. Of these there are two main systems: (1) a continuous cable is carried over two main drums at each end of the line, and the motion is derived either (a) from the weight of the descending load or (b) from a motor acting on one of the main drums; (2) each end of the cable is attached to wagons, one set of which accordingly ascends as the other descends. The weight required to cause the downward motion is obtained either by means of the material which has to be transported to the bottom of the hill or by water ballast, while to aid and regulate the motion generally steam or electric motors are arranged to act on the main drums, round which the cable is passed with a sufficient number of turns to prevent slipping. When water ballast is employed the water is filled into a tank in the bottom of the wagon or car, its quantity, if passengers are carried, being regulated by the number ascending or descending.

The curves on railways are either simple, when they consist of a portion of the circumference of a single circle, or compound, when they are made up of portions of the circumference of two or more circles of different radius. Reverse curves are compound curves in which the components are of contrary flexure, like the letter S; strictly the term is only applicable when the two portions follow directly one on the other, but it is sometimes used of cases in which they are separated by a " tangent " or portion of straight line. In Great Britain the curvature is defined by stating the length of the radius, expressed in chains (i chain=66 ft.), in America by stating the angle subtended by a chord ioo ft. long; the measurements in both methods are referred to the central line of the track. The radius of a 1-degree curve is 5730 ft., or about 861 chains, of a 15-degree curve 383 ft. or rather less than 6 chains; the former is reckoned easy, the latter very sharp, at least for main lines on the standard gauge. On some of the earlierEnglish main lines no curves were constructed of a less radius than a mile (80 chains), except at places where the speed was likely to be low, but in later practice the radius is sometimes reduced to 40 or 30 chains, even on high-speed passenger lines.

When a train is running round a curve the centrifugal force which comes into play tends to make its wheel-flanges press against the outer rail, or even to capsize it. If this pressure is not relieved in some way, the train may be derailed either (I) by " climbing " the outer rail, with injury to that rail and, generally, to the corresponding wheel-flanges; (2) by overturning about the outer rail as a hinge, possibly without injury to rails or wheels; or (3) by forcing the outer rail outwards, occasionally to the extent of shearing the spikes that hold it down at the curve, thus spreading or destroying the track. In any case the details depend upon whether the vehicle concerned is an engine, a wagon or a passenger coach, and upon whether it runs on bogie-trucks or not. If it is an engine, particular attention must be directed to the type, weight, arrangement of wheels and height of centre of gravity above rail level. In considering the forces that produce derailment the total mass of the vehicle or locomotive may be supposed to be concentrated at its centre of gravity. Two lines may be drawn from this point, one to each of the two rails, in a plane normal to the rails, and the ends of these lines, where they meet the rails, may be joined to complete a triangle, which may conveniently be regarded as a rigid frame resting on the rails. As the vehicle sweeps round the curve the centre of gravity tends to be thrown outwards,. like a stone from a horizontal sling. The vertical pressure of the frame upon the outer rail is thus increased, while its vertical pressure on the inner rail is diminished. Simultaneously the frame as a whole tends to slide horizontally athwart the rails,. from the inner towards the outer rail, urged by the same centrifugal forces. This sliding movement is resisted by placing a check rail on the inner side of the inner rail, to take the lateral thrust of the wheels on that side. It is also resisted in part by the conicity of the wheels, which converts the lateral force partly into a vertical force, thus enabling gravity to exert a. restoring influence. When the lateral forces are too great to be controlled " climbing " occurs. Accidents due to simple climbing are, however, exceedingly rare, and are usually found associated with a faulty track, with " plunging " movements of the locomotive or vehicle, or with a " tight gauge " at curves or points.

From consideration of the rigid triangular frame described above, it is clear that the " overturning " force acts horizontally from the centre of gra'Vity, and that the length of its lever arm is, at any instant, the vertical distance from the centre of gravity to the level of the outer rail. This is true whatever be the tilt of the vehicle at that instant. The restoring force exerted by gravity acts in a vertical line from the centre of gravity; and the length of its lever arm is the horizontal distance between this vertical line and the outer rail. If therefore the outer rail is laid at a level above that of the inner rail at the curve, overturning will be resisted more than would be the case if both rails were in the same horizontal plane, since the tilting of the vehicle due to this " superelevation " diminishes the overturning moment, and also increases the restoring moment, by shortening in the one case and lengthening in the other the lever arms at which the respective forces act. The amount of superelevation required to prevent derailment at a curve can be calculated under perfect running conditions, given the radius of curvature, the weight of the vehicle, the height of the centre of gravity, the distance between the rails, and the speed; but great experience 1 See The Times Engineering Supplement (August 22, 1906), p. 265.

is required for the successful application of definite formulae to the problem. For example, what is a safe speed at a given curve for an engine, truck or coach having the load equally distributed over the wheels may lead to either climbing or overturning if the load is shifted to a diagonal position. An ill-balanced load also exaggerates " plunging," and if the period of oscillation of the load happens to agree with the changes of contour or other inequalities of the track vibrations of a dangerous character, giving rise to so-called " sinuous " motion, may occur.

In general it is not curvature, but change of curvature, that presents difficulty in the laying-out of a line. For instance, if the curve is of S-form, the point of danger is when the train enters the contra-flexure, and it is not an easy matter to assign the best superelevation at all points throughout the double bend. Closely allied to the question of safety is the problem of preventing jolting at curves; and to obtain easy running it is necessary not merely to adjust the levels of the rails in respect to one another, but to tail off one curve into the next in such a :nanner as to avoid any approach to abrupt lateral changes of direction. With increase of speeds this matter has become important as an element of comfort in passenger traffic. As a first approximation, the centre-line of a railway may be plotted out as a number of portions of circles, with intervening straight tangents connecting them, when the abruptness of the changes of direction will depend on the radii of the circular portions. But if the change from straight to circular is made through the medium of a suitable curve it is possible to relieve the abruptness, even on curves of comparatively small radius. The smoothest and safest running is, in fact, attained when a " transition," " easement " or " adjustment " curve is inserted between the tangent and the point of circular curvature.

For further information see the following papers and the discussions on them: " Transition Curves for Railways," by James Glover, Proc. Inst. C.E. vol. 140, part ii.; and " High Speed on Railway Curves," by J. W. Spiller, and " A Practical Method for the Improvement of Existing Railway Curves," by W. H. Shortt, Proc. Inst. C.E. vol. 176, part ii.

The gauge of a railway is the distance between the inner edges of the two rails upon which the wheels run. The width of 4 ft. 82 in. may be regarded as standard, since it prevails on probably three-quarters of the railways of the globe. In North America, except for small industrial railways and some short lines for local traffic, chiefly in mountainous country, it has become almost universal; the long lines of 3 ft. gauge have mostly been converted, or a third rail has been laid to permit interchange of vehicles, and the gauges of 5 ft. and more have disappeared. A considerable number of lines still use 4 ft. 9 in., but as their rolling stock runs freely on the 4 ft. 81 in. gauge and vice versa, this does not constitute a break of gauge for traffic purposes. The commercial importance of such free interchange of traffic is the controlling factor in determining the gauge of any new railway that is not isolated by its geographical position. In Great Britain railways are built to gauges other than 4 ft. 82 in. only under exceptional conditions; the old " broad gauge " of 7 ft. which I. K. Brunel adopted for the Great Western railway disappeared on the 20th-23rd of May 1892, when the main line from London to Penzance was converted to standard gauge throughout its length. In Ireland the usual gauge is 5 ft. 3 in., but there are also lines laid to a 3 ft. gauge. On the continent of Europe the standard gauge is generally adopted, though in France there are many miles of 4 ft. 9 in. gauge; the normal Spanish and Portuguese gauge is, however, 5 ft. 54 in., and that of Russia 5 ft. In France and other European countries there is also an important mileage of metre gauge, and even narrower, on lines of local or secondary importance. In India the prevailing gauge is 5 ft. 6 in., but there is a large mileage of other gauges, especially metre. In the British colonies the prevailing gauge is 3 ft. 6 in., as in South Africa, Queensland, Tasmania and New Zealand; but in New South Wales the normal is 4 ft. 82 in. and in Victoria.

5 ft. 3 in., communication between different countries of the Australian Commonwealth being thus carried on under the disadvantage of break of gauge. Though the standard gauge is in use in Lower Egypt, the line into the Egyptian Sudan was built on a gauge of 3 ft. 6. in., so that if the so-called Cape to Cairo railway is ever completed, there will be one gauge from Upper Egypt to Cape Town. In South America the 5 ft. 6 in. gauge is in use, with various others.

The gauge may be regarded as reduced to its narrowest possible dimensions in mono-rail lines, where the weight of the trains is carried on a single rail. This method of construction, however, has been adopted only to a very limited extent. In the Lartigue system the train is straddled over a single central rail, elevated a suitable distance above the ground. A short line of this kind runs from Ballybunnion to Listowel in Ireland, and a more ambitious proje c t on the same principle, on the plans of Mr F. C. Behr, to connect Liverpool and Manchester, was sanctioned by Parliament in 1901. In this case electricity was to be the motive-power, and speeds exceeding ioo m. an hour were to be attained, but the line has not been built. In the Langen mono-rail the cars are hung from a single overhead rail; a line on this system works between Barmen and Elberfeld, about 9 m., the cars for a portion of the distance being suspended over the river Wupper. In the system devised by Mr Louis Brennaxi the cars run on a single rail laid on the ground, their stability being maintained by a heavy gyrostat revolving at great speed in a vacuum.

Permanent Way. - When the earth-works of a line have been completed and the tops of the embankments and the bottoms of the cuttings brought to the level decided upon, the next step is to lay the permanent way, so-called probably in distinction to the temporary way used during construction. The first step is to deposit a layer of ballast on the road-bed or " formation," which often slopes away slightly on each side from the central line to facilitate drainage. The ballast consists of such materials as broken stone, furnace slag, gravel, cinders or earth, the lower layers commonly consisting of coarser materials than the top ones, and its purpose is to provide a firm, well-drained foundation in which the sleepers or crossties may be embedded and held in place, and by which the weight of the track and the trains may be distributed over the road-bed. Its depth varies, according to the traffic which the line has to bear, from about 6 in. to i ft. or rather more under the sleepers, and the materials of the surface layers are often chosen so as to be more or less dustless. Its width depends on the numbers of tracks and their gauge; for a double line of standard gauge it is about 25 ft., a space of 6 ft. (" sixfoot way ") being left between the inner rails of each pair in Great Britain (fig. 8), and a rather larger distance in America k FIG. 8. - Half of English Double Track.

(fig. 9), where the over-hang of the rolling stock is greater. The intervals between the sleepers are filled in level with ballast, 12'2' FIG. 9. - Hjilf of American Double Track.

which less commonly is also heaped up over them, especially at the projecting ends.

Sleepers, called ties or cross-ties in America, are the blocks or slabs on which the rails are carried. They are nearly always placed transversely, across the direction of the lines, the longitudinal position such as was adopted in connexion with the broad gauge on the Great Western in England having been abandoned except in special cases. Stone blocks were tried as sleepers in the early days of railways, but they proved too rigid, and besides, it was found difficult to keep the line true with them. Wood is the material most widely used, but steel is employed in some countries where timber is scarce or liable to destruction by white ants, though it is still regarded as too expensive in comparison with wood for general adoption. Steel sleepers were used experimentally on the London & 'Forth-Western, but were abandoned owing to the shortness of their life. In Germany, where they have met with greater favour, there were over 261 millions in use in 1905, 1 and they I ave been tried by some American railways. Numerous forms of ferro-concrete sleepers have also been devised.

In Great Britain, Germany and France, at least 90% of the wooden sleepers are " treated " before they are laid, to ii.crease their resistance to decay, and the same practice is followed to some extent in other European countries. A great number of preservative processes have been devised. In that most largely used, known as " creosoting," dead oil of tar, to the amount of some 3 gallons per sleeper, is forced into the wood under pressure, or is sucked in by vacuum, both the timber and the oil being heated. In the United States only a small percentage of the ties are treated in any way beyond seasoning in the open air, timber, in the opinion of the railway officials, being still too cheap in nearly all parts of that country to justify the use of preservatives. Some railway companies, however, having a long mileage in timberless regions, do " treat " their sleepers.

Typical dimensions for sleepers on important British railways are: - length 9 ft., breadth io in., and depth 5 in. In America 8 ft. is the most common length, the breadth being 8 in., and the depth 6 or 7 in.

There are two main ways of attaching the rails to the sleepers, corresponding to two main types of rails - the bull-headed rail A B FIG. 10. - A, Section of British Bull-Headed Rail, 90 lb to the yard, showing also chair and fastenings. B, Plan of Chair.

and the Vignoles or flange rail. In the first method, which is practically universal in Great Britain and is also employed to 1 See a full account of steel sleepers in a paper read by A. Haarmann before the Verein der Deutschen Eisenhuttenleute on Dec. 8, 1907, translated in the Railway Gazette (London) on April 3, 10 and 17, 1908.

some extent in France and India, the rails have rounded bases and are supported by being wedged, with wooden keys, in castiron chairs which are bolted to the sleepers. In the second method the rails have flat flanged bases which rest directly on the sleepers (fig. io). The chairs on the British system weigh about 45 or 50 lb each on important lines, though they may be less where the traffic is light, and are fixed to the sleepers each by two, three or four fastenings, either screw spikes, or round drift bolts entered in holes previously bored, or fang bolts or wooden trenails. Sometimes a strip of felt is interposed between the chair and the sleeper, and sometimes a serrated surface is prepared on the sleeper for the chair which is forced into its seat by hydraulic pressure. The keys which hold the rail in the chairs are usually of oak and are placed outside the rails; the inside position has also been employed, but has the disadvantage of detracting from the elasticity of the road since the weight of a passing train presses the rails up against a rigid mass of metal instead of against a slightly yielding block of wood. The rails, which for heavy main line traffic may weigh as much as too lb per yard, or even more, are rolled in lengths of from 30 to 60 ft., and sleepers are placed under them at intervals of between 2 and 3 ft. (centre to centre), 11 sleepers to a 30 ft. rail being a common arrangement. On the London & North-Western railway there are 24 sleepers to each 60 ft. rail. A small space is left between the end of one rail and that of the next, in order to allow for expansion in hot weather, and at the joint the two are firmly braced together by a pair of fish-plates (fig.ri). These are flat bars of iron or steel from 18 in. to 2 ft. long, which are lodged in the channels of the rail, one on each side, and secured with four bolts passing through the web; sometimes, to give additional stiffness, they extend down below the lower table of the rail and are bent round so as to clip it. Occasionally the joints thus formed are " supported " on a sleeper, as was the practice in the early days of railway construction, but they are generally " suspended " between two sleepers, which are set rather more closely together than at other points in the rail. Preferably, they are so arranged that those in both lines of rails come opposite each other and are placed between the same pair of sleepers.

Flat-bottomed rails are fastened to the sleepers by hookheaded spikes, the heads of which project over the flanges. In the United States the spikes are simply driven in with a maul, and the rails stand upright, little care being taken to prepare seats for them on the sleepers, on which they soon seat themselves. The whole arrangement is simple and cheap in first cost, and it lends itself admirably to fast track-laying and to repairs and changes of line. On the continent of Europe the practice is common of notching the sleeper so as to give the rail a slight cant inwards - a result obtained in England by canting the rail in the chairs - and metal plates or strips of felt are put under the rail, which is carefully fastened to the sleeper by screwed spikes (fig. 12). This method of construction is more FIG. 12. - French Rail, 901 lb to the yard, showing rail joint and seat in the sleeper.

expensive than the American in first cost, but it gives a more durable and stable track. Such metal plates, or " tie-plates," have come into considerable use also in the United States, where they are always made of rolled steel, punched with rectangular holes through which the spikes pass. They serve two principal FIG. I I. - British Rail and Rail Joint.

purposes: they diminish the wear of the sleeper under the rail by providing a larger bearing surface, and they help to support the spikes and so to keep the gauge. On all the accepted forms there are two or more flanges at the bottom, running lengthwise of the plate and crosswise of the rail; these are requisite to give proper stiffness, and further, as they are forced into the tie by the weight of passing traffic, they help to fix the plate securely in place. The joints of flanged rails are similar to those employed with bull-headed rails. Various forms, mostly patented, have been tried in the United States, but the one most generally adopted consists of two symmetrical angle bars (fig. 13), varying in length (from 20 to 48 in.), in weight and in the number of bolts, which may be four or six.

The substitution of steel for iron as the material for rails which made possible the axle loads and the speeds of Lto-day, and, by reducing the cost of maintenance, contributed enormously to the economic efficiency of railways, was one of the most important events in the history of railways, and a scarcely less important element of progressive economy has been the continued improvement of the steel rail in stiffness of section and in toughness and hardness of material. Carbon is the important element in controlling hardness, and the amount present is in general higher in the United States than in Great Britain. The specifications for bull-headed rails issued by the British Engineering Standards Committee in 1904 provided for a carbon-content ranging from 0-35 to 0-50%, with a phosphorus maximum of 0.075%. In the United States a committee of the American Society of Civil Engineers, appointed to consider the question of rail manufacture in consequence of an increase in the number of rail-failures, issued an interim report in 1907 in which it suggested a range of carbon from 0-55 to 0-65% for the heaviest sections of Bessemer steel flange rails, with a phosphorus maximum of 0.085%; while the specifications of the American Society for Testing Materials, current at the same period, put the carbon limits at o45 to 0-55%, and the phosphorus limit at oio. For rails of basic open-hearth steel, which is rapidly ousting Bessemer steel, the Civil Engineers' specifications allowed from o65 to 0-75% of carbon with 0-05% of phosphorus, while the specifications of the American Railway Engineering and Maintenance of Way Association provided for a range of 0.75 to 0-85% of carbon, with a maximum of 0.03% of phosphorus. The rail-failures mentioned above also drew renewed attention to the importance of the thermal treatment of the steel from the time of melting to the last passage through the rolling mill and to the necessity of the finishing temperature being sufficiently low if the product is to be fine grained, homogeneous and tough; and to permit of this requirement being met there was a tendency to increase the thickness of the metal in the web and flanges of the rails. The standard specification adopted by the Pennsylvania railway in 1908 provided that in rails weighing Ioo lb to the yard 41% of the metal should be in the head, 18-6% in the web, and 40-4% in the base, while for 85 lb rails 42.2% was to be in the head, 17-8% in the web and 40.0% in the base. These rails were to be rolled in 33-ft. lengths. According to the specification for 85 lb rails adopted by the Canadian Pacific railway about the same time, 36-77% of the metal was to be in the head, 22'21% in the web and 4102% in the base.

To enable trains to be transferred from one pair of rails to another pair, as from the main line to a siding, " points " or " switches " are provided. At the place where the four rails come together, the two inner ones (one of the main line and the other of the siding), known as " switch rails " (b, fig. 14), are tapered to a fine point or tongue, and rigidly connected together at such a distance apart that when one of the points is pressed against the outer or "stock" rail (a) of either the siding or the main line there is sufficient space between the other tongue and the other stock rail to permit the free passage of the flanges of the wheels on one side of the train, while the flanges on the other side find a continuous path along the other switch rail and thus are deflected in the desired direction. The same arrangement is employed at junctions where different running lines converge. The points over which a train travels when directed from the main to a branch line are called " facing points " (F P), while those which it passes when running from a branch to a main line are " trailing points " (TP). In Great Britain the Board of Trade requires facing points to be avoided as far as possible; but, of course, they are a necessity at junctions where running lines diverge and at the crossing places which must be provided to enable trains to pass each other on single-track lines. At stations the points that give access to sidings are generally arranged as trailing points with respect to the direction of traffic on the main lines; that is, trains cannot pass direct into sidings, but have to stop and then run backwards into them. In shunting yards the points are commonly set in the required direction by means of hand levers placed close beside the lines, but those at junctions and those which give access from the main lines to sidings at wayside stations are worked by a system of rods from the signal cabin, or by electric or pneumatic power controlled from it and interlocked with the signals (see Signal: § Railway). Crossings are inevitable adjuncts of points. Where a branch diverges from a main line, one rail of the one must cross one rail of the other, and a V-crossing is formed (V). Where, as at a double-line junction, one pair of rails crosses another pair, " diamond " crossings (p) are formed. At both types of crossing, check rails (c) must be provided to guide the wheel-flanges, and if these are not accurately placed the safety of the trains will be endangered. At double-line junctions trains passing over the diamond crossings evidently block traffic going in the opposite direction to that in which they are travelling. To avoid the delay thus caused the branch line which would occasion the diamond crossing if it were taken across on the level is sometimes carried over the main line by an over-bridge (" flying junction ") or under it by an under-bridge (" burrowing junction ").

Railway stations are either " terminal " or " intermediate." A terminal station embraces (I) the passenger station; (2) the goods station; (3) the locomotive, carriage and waggon depots, where the engines and the carrying stock are kept, cleaned, examined and repaired. At many intermediate stations the same arrangements, on a smaller scale, are made; in all of them there is at least accommodation for the passenger and the goods traffic. The stations for F - FIG. Q. - American Rail, 90 lb to the yard, showing rail joint.

FIG. 14. - Points and Crossings. FP =Facing points.

TP =Trailing points.

a=Stock rail.

b =Switch rail.

V =Single or V-crossing. D= Diamond crossing.

c = Check rails.

d = Wing rails.

e = Winged check rails.

f = Diamond points.

passengers and goods are generally in different and sometimes in distant positions, the place selected for each being that which is most convenient for the traffic. The passenger station abuts on the main line, or, at termini, forms the natural terminus, at a place as near as can conveniently be obtained to the centre of the population which constitutes the passenger traffic; and preferably its platforms should be at or near the ground level, for convenience of access. The goods station is approached by a siding or fork set off from the main line at a point short of the passenger station. In order to keep down the expense of shunting the empty trains and engines to and from the platforms the carriage and locomotive depots should be as near the passenger station as possible; but often the price of land renders it impracticable to locate them in the immediate vicinity and they are to be found at a distance of several miles.

In laying out the approaches and station yard of a passenger station ample width and space should be provided, with welldefined means of ingress and egress to facilitate the Passenger ci rculation of vehicles and with a long setting-down stations. g g pavement to enable them to discharge their passengers and luggage without delay. The position of the main buildings - ticket offices, waiting and refreshment-rooms, parcels offices, &c. - relative to the direction of the lines of rails may be used as a means of classifying terminal stations. They are placed either on the departure side parallel to the platform (" side " stations) or at right angles to the rails and platforms (" end " stations). Many large stations, however, are of a mixed type, and the offices are arranged in a fork between two or more series of platforms, or partly at the end and partly on one side. Where heavy suburban traffic has to be dealt with, the expedient is occasionally adopted of taking some of the lines round the end in a continuous loop, so that incoming trains can deposit their passengers at an underground platform and immediately proceed on their outward journey. Intermediate stations, like terminal ones, should be convenient in situation and easy of approach, and, especially if they are important, should be on the ground level rather than on an embankment or in a cutting. The lines through them should be, if possible, straight and on the level; the British Board of Trade forbids them being placed on a gradient steeper than i in 260, unless it is unavoidable. Intermediate stations at the surface level are. naturally constructed as side stations, and whether offices are provided on both sides or whether they are mainly concentrated on one will depend on local circumstances, the amount of the traffic, and the direction in which it preponderates. When the railway lies below the surface level the bulk of the offices are often placed on a bridge spanning the lines, access being given to the platforms by staircases or lifts, and similarly when the railway is at a high level the offices may be arranged under the lines. Occasionally on a double-track railway one platform placed between the tracks serves both of them; this " island " arrangement, as it is termed, has the advantage that more tracks can be readily added without disturbance of existing buildings, but when it is adopted the exit from the trains is at the opposite side to that which is usual, and accidents have happened through passengers alighting at the usual side without noticing the absence of a platform. At stations on double-track railways which have a heavy traffic four tracks are sometimes provided, the two outside ones only having platforms, so that fast trains get a clear road and can pass slow ones that are standing in the station. In Great Britain, it may be noted, trains almost invariably keep to the left, whereas in most other countries right-handed running is the rule.

The arrangement and appropriation of the tracks in a station materially affect the economical and efficient working of the traffic. There must be a sufficient provision of sidings, connected with the running tracks by points, for holding spare rolling stock and to enable carriages to be added to or taken off trains and engines to be changed with as little delay as possible. At terminal stations, especially at such as are used by short-distance trains which arrive at and start from the same platform, a third track is often laid between a pair of platform tracks, so that the engine of a train which has arrived at the platform can pass out and place itself at the other end of the train, which remains undisturbed. At the new Victoria station (London) of the London, Brighton & South Coast railway - which is so long that two trains can stand end to end at the platforms - this system is extended so as to permit a train to start out from the inner end of a platform even though another train is occupying the outer end. One of the advantages of electric trains on the multiple control system is that they economize terminal accommodation, because they can be driven from either end indifferently, and therefore avoid the necessity for tracks by which engines can change from one end of the train to the other.

The platforms on British railways have a standard elevation of 3 ft. above rail level, and they are not now made less than 2 ft. in height. In other countries they are generally lower; in the United States they are commonly level with, or only a few inches higher than, the top of the rails. They may consist of earth with a retaining wall along the tracks and with the surface gravelled or paved with stone or asphalt, or they may be constructed entirely of timber, or they may be formed of stone slabs supported on longitudinal walls. They should be of ample dimensions to accommodate the traffic - the British Board of Trade requires them to be not less than 6 ft. wide at small stations and not less than 12 ft. wide at large ones - and they should be as free as possible from obstructions, such as pillars supporting the roof. At intermediate stations the roofs are often carried on brackets fixed to the walls of the station buildings, and project only to the edge of the platforms. At larger stations where both the platforms and the tracks are covered in, there are two broad types of construction, with many intermediate variations: the roof may either be comparatively low, of the " ridge and furrow " pattern, borne on a number of rows of pillars, or it may consist of a single lofty span extending clear across the area from the side walls. The advantage claimed for roofs formed with one or two large spans is that they permit the platforms and tracks to be readily rearranged at any time as required, whereas this is difficult with the other type, especially since the British Board of Trade requires the pillars to be not less than 6 ft. away from the edges of the platforms. On the other hand, wide spans are more expensive both in first cost and in maintenance, and there is the possibility of a failure such as caused the collapse in December 1905 of the roof of Charing Cross (S.E.R.) station, London, which then consisted of a single span. Whatever the pattern adopted for the roof, a sufficient portion of it must be glazed to admit light, and it should be so designed that the ironwork can be easily inspected and painted and the glass readily cleaned. For the illumination of large stations by night electric arc lamps are frequently employed, but some authorities favour high-pressure incandescent gas-lighting.

At busy stations separate tracks are sometimes appropriated to the use of light engines and empty trains, on which they may be run between the platforms and the locomotive and Loco- carriage depots. A carriage depot includes sheds in motive which the vehicles are stored, arrangements for wash- depots. ing and cleaning them, and sidings on which they are marshalled into trains. At a locomotive depot the chief building is the " running shed " in which the engines are housed and cleaned. This may be rectangular in shape (" straight " shed), containing a series of parallel tracks on which the engines stand and which are reached by means of points and crossings diverging from a main track outside; or it may take a polygonal or circular form (round house or rotunda), the lines for the engines radiating from a turn-table which occupies the centre and can be rotated so as to serve any of the radiating lines. The second arrangement enables any particular engine to enter or leave without disturbing the other; but on the other hand an accident to the turn-table may temporarily imprison the whole of them. In both types pits are constructed between the rails on which the engines stand to afford easy access for the inspection and cleaning of their mechanism. Machine shops are usually provided to enable minor repairs to be executed; the tendency, both in England and America, is to increase the amount of such repairing plant at engine sheds, thus lengthening the intervals between the visits of the engines to the main repairing shops of the railway. A locomotive depot further includes stores of the various materials required in working the engines, coal stages at which they are loaded with coal, and an ample supply of water. The quality of the last is a matter of great importance; when it is unsuitable, the boilers will suffer, and the installation of a water-softening plant may save more in the expenses of boiler maintenance than it costs to operate. The water cranes or towers which are placed at intervals along the railway to supply the engines with water require similar care in regard to the quality of the water laid on to them, as also to the water troughs, or track tanks as they are called in America, by which engines are able to pick up water without stopping. These consist of shallow troughs about 18 in. wide, placed between the rails on perfectly level stretches of line. When water is required, a scoop is lowered into them from below the engine, and if the speed is sufficient the water is forced up it into the tender-tanks. Such troughs were first employed on the London & North-Western railway in 1857 by John Ramsbottom, and have since been adopted on many other lines.

Goods stations vary in size from those which consist of perhaps a single siding, to those which have accommodation for thousands of wagons. At a small roadside station, where the traffic is of a purely local character, there will be some sidings to which horses and carts have access for handling bulk goods like coal, gravel,. manure, &c., and a covered shed for loading and unloading packages and materials which it is undesirable to expose to the weather. The shed may have a single pair of rails for wagons running through it along one side of a raised platform, there being a roadway for carts on the other side; or if more accommodation is required there may be two tracks, one on each side of the platform, which is then approached by carts at the end. In either case the platform is fitted with a crane or cranes for lifting merchandise into and out of the wagons, and doors enable the shed to be used as a lock-up warehouse. In a large station the arrangements become much more complicated, the precise design being governed by the nature of the traffic that has to be served and by the physical configuration of the site. It is generally convenient to keep the inwards and the outwards traffic distinct and to deal with the two classes separately; at junction stations it may also be necessary to provide for the transfer of freight from one wagon to another, though the bulk of goods traffic is conveyed through to its destination in the wagons into which it was originally loaded. The increased loading space required in the sheds is obtained by multiplying the number and the length of lines and platforms; sometimes also there are short sidings, cut into the platforms at right angles to the lines, in which wagons are placed by the aid of wagon turn-tables, and sometimes the wagons are dealt with on two floors, being raised or lowered bodily from the ground level by lifts. The higher floors commonly form warehouses where traders may store goods which have arrived or are awaiting despatch. An elaborate organization is required to keep a complete check and record of all the goods entering and leaving the station, to ensure that they are loaded into the proper wagons according to their destination, that they are unloaded and sorted in such a way that they can be delivered to their consignees with the least possible delay, that they are not stolen or accidentally mislaid, &c.; and accommodation must be provided for a large clerical and supervisory staff to attend to these matters. British railways also undertake the collection and delivery of freight, in addition to transporting it, and thus an extensive range of vans and wagons, whether drawn by horses or mechanically propelled, must be provided in connexion with an important station.

It may happen that from a large station sufficient traffic may be consigned to certain other large stations to enable full train-loads to be made up daily, or several times a day, and despatched direct to their destinations. In general, however, the conditions are less simple. Though a busy colliery may send off its product by the train-load to an important town, the wagons will usually be addressed to a number of different consignees at different depots in different parts of the town, and therefore the train will have to be broken up somewhere short of its destination and its trucks rearranged, together with those of other trains similarly constituted, into fresh trains for conveyance to the various depots. Again, a: station of moderate size may collect goods destined for a great variety of places but not in sufficient quantities to compose a full train-load for any of them, and then it becomes impossible; except at the cost of uneconomical working, to avoid despatching trains which contain wagons intended for many diverse destinations. For some distance these wagons will all travel over the same line, but sooner or later they will reach a junction-point where their ways will diverge and where they must be separated. At this point trains of wagons similarly destined for different places will be arriving from other lines, and hence the necessity will arise of collecting together from all the trains all the wagons which are travelling to the same place.

The problem may be illustrated diagrammatically as follows` (fig. 15): A may be supposed to be a junction outside a large FIG. 15. - Diagram to illustrate use of Shunting Yards.

seaport where branches from docks a, b, c and d converge, and where the main line also divides into three, going to B, C and D respectively. A train from a will contain some wagons for B,, some for C and some for D, as will also the trains from a, b, c and d. At A therefore it becomes necessary to disentangle and group together all the wagons that are intended for B, all that are intended for C, and all that are intended for D. Even that is not the whole of the problem. Between A and B, A and C, and A and D, there may be a string of stations, p, q, r, s, &c., all receiving goods from a, b, c and d, and it would manifestly be inconvenient and wasteful of time and trouble if the trains serving those intermediate stations were made up with, say, six wagons from a to p next the engine, five from b to p at the middle, and four from c to p near the end. Hence at A the trucks from a, b, c and d must not only be sorted according as they have to travel along A B, A C, or A D, but also must be marshalled into trains in the order of the stations along those lines. Conversely, trains arriving at A from B, C and D must be broken up. and remade in order to distribute their wagons to the different, dock branches.

To enable the wagons to be shunted into the desired order yards containing a large number of sidings are constructed at important junction points like A. Such a yard consists essentially of a group.. or groups of sidings, equal in length at least to the longest train run on the line, branching out from a single main track and often again converging to a single track at the other end; the precise design,.. however, varies with the amount and character of the work that has to be done, with the configuration of the ground, and also with the mode of shunting adopted. The oldest and commonest method of shunting is that known as " push-and-pull," or in America as " link-and-pin " or " tail " shunting. An engine coupled to a batch of wagons runs one or more of them down one siding, leaves them there, then returns back with the remainder clear of the points where the sidings diverge, runs one or more others down another siding, and so on till they are all disposed of. The same operation is repeated with fresh batches of wagons, until the sidings contain a number of trains, each intended, it may be supposed, for a particular town or district. In some cases nothing more is required than to attach an engine and brake-van (" caboose ") and despatch the train; but if, as will happen in others, a further rearrangement of XXII. 27 a the wagons is necessary to get them into station order this is effected on the same principle.

Push-and-pull shunting is simple, but it is also slow, and therefore efforts have been made at busy yards where great numbers of trains are dealt with to introduce more expeditious methods. One of these, employed in America, is known as " poling." Alongside the tracks on which stand the trains that are to be broken up and from which the sidings diverge subsidiary tracks are provided for the use of the shunting engines. These engines have a pole projecting horizontally in front of them, or are attached to a " polecar " having such a pole. The method of working is for the pole to be swung out behind a number of wagons; one engine is then started and with its pole pushes the wagons in front of it until their speed is sufficient to carry them over the points, where they are diverted into any desired siding. It then runs back to the train to repeat the operation, but while it is doing so a second engine similarly equipped has poled away a batch of wagons on the opposite side. In this way a train is distributed with great rapidity, especially if the points giving access to the different sidings are worked by power so that they can be quickly manipulated.

Another method, which was introduced into America from Europe about 1890, is that of the summit or " hump." The wagons are pushed by an engine at their rear up one slope of an artificial mound, and as they run down the other slope by gravity are switched into the desired siding. Sometimes a site can be found for the sorting sidings where the natural slope of the ground is sufficiently steep to make the wagons run down of themselves. One of the earliest and best known of such " gravity " yards is that at Edgehill, near Liverpool, on the London & North-Western railway, which was established in 1873. Here, at the highest level, there are a number of " upper reception lines " converging to a single line which leads to a group of " sorting sidings " at a lower level. These in turn converge to a pair of single lines which lead to two groups of marshalling sidings, called " gridirons " from their shape, and these again converge to single lines leading to " lower reception and departure lines " at the bottom of the slope. The wagons from the upper reception lines are sorted into trains on the sorting sidings, and then, in the gridirons, are arranged in the appropriate order and marshalled ready to be sent off from the departure lines. (H. M. R.) Locomotive Power The term " power " is used in technical sense to mean the rate at which work is done against a resistance, and is measured in units of energy expended per unit of time. The unit of power commonly used by engineers is the horse-power, and this unit corresponds to a rate of working of 550 foot-lb of work per second. The problems arising out of the special consideration of the power required to propel a railway train against the resistances opposing its motion, the way the power is applied to trains, the agent by means of which the power is exerted, are conveniently grouped together under the general heading of Locomotive Power. There are certain fundamental relations common to all tractive problems, and these are briefly considered in §§ i and 2, after which the article refers particularly to steam locomotives, although §§ 4, 5, 7, 8, 9, and 10 have a general application to all modes of traction.

§ 1. Fundamental Relations. - The resistance against which a train is moved along a railway is overcome by means of energy obtained from the combustion of fuel, or in some few cases by energy obtained from a waterfall. If the total resistance against which the train is maintained in motion with an instantaneous velocity of V feet per second is R, the rate at which energy is expended in moving the train is represented by the product RV, and this must be the rate at which energy is supplied to the train after deducting all losses due to transmission from the source of power. Thus if R is equal to 10,000 lb when the velocity is 44 ft. per second, equivalent to 30 m. per hour, the rate of working against the resistance is 440,000 foot-lb per second.

In whatever form energy is produced and distributed to the train it ultimately appears as mechanical energy applied to turn one or more axles against the resistance to their rotation imposed by the weight on the wheels and the motion of the train.

The rate at which work is done on a particular axle is measured by the product where T is the torque or turning moment exerted on the axle by the motor or mechanism applied to it for this purpose, and is the angular velocity of the axle in radians per second. Hence if all the energy supplied to the train is utilized at one axle there is the fundamental relation RV (I) Continuing the above arithmetical illustration, if the wheels to the axle of which the torque is applied are 4 ft. diameter, w = 44/2 = 22 radians per second, and therefore T= 440,000/22=20,000 lb ft. If the energy supplied is distributed between several axles the relation becomes l l 2 3 w 3. = RV (2) where T 1, T2, T3, &c. are the torques on the axles whose respective angular velocities are wl,w2, W3, &c.

The fundamental condition governing the design of all tractive machinery is that the wheels belonging to the axles to which torque is applied shall roll along the rails without slipping, and exert a tractive force on the train.

The fundamental relation between the applied torque and the tractive force F will be understood from fig. 16, which shows in a diagrammatic form a wheel and axle connected to the framework of a vehicle, in the way adopted for railway trains. The journal of the axle A, is carried in a bearing or axle-box B, which is free to move vertically in the wide vertical slot G, formed in the frame and called generally " the horns," under the control of the spring. The weight W 1 carried by the part of the frame supported by the wheel (whose diameter is D) is transmitted first to the pins P 1, P2, which are fixed to the frame, and then to the spring links L 1, L2, which are jointed at their respective ends to the spring S, the centre of which rests on the axle-box.

Let a couple be applied to the axle tending to turn it in the direction shown by the arrow. This couple, we may assume, will be equally divided between the two wheels, so that the torque acting on each will be T. Assuming the wheels to roll along the rail without slipping, this couple will be equivalent to the couple formed by the equal opposite and parallel forces, F 1 acting in the direction shown, from the axle-box on to the frame, and F 1 =µ0, acting along the rail. The torque corresponding to this couple is F 1 X z D = 2µWID, and hence follows the fundamental relation, 2T = 2F 1 D = 2µWID, or if W now represents the weight supported by the axle, F will be the tractive force exerted on the frame by the two axle-boxes to propel the vehicle, and the more convenient relation is established, T=2FD=2µWD (3) If T has a greater value than this relation justifies the wheels will slip. F is called the " tractive force " at the rail. The coefficient of friction is a variable quantity depending upon the state of the rails, but is usually taken to be This is the fundamental equation between the forces acting, however the torque may be applied. Multiplying through by w we obtain Tw = 2FwD = 2µWwD = RV (4) This is a fundamental energy equation for any form of locomotive in which there is only one driving-axle.

The couple T is necessarily accompanied by an equal and opposite couple acting on the frame, which couple endeavours to turn the frame in the opposite direction to that in which the axle rotates. The practical effect of this opposite couple is slightly to tilt the frame and thus to redistribute slightly the weights on the wheels carrying the vehicle.

If there are several driving-axles in a train, the product Tw must be estimated for each separately; then the sum of the products will be equal to RV. In equation (4) there is a fixed relation between w, V and D given by the expression.

w=2V /D (5) Here D is in feet, V in feet per second and w in radians per second. If the speed is given in miles per hour, S say, V =1.466 S (6) The revolutions of the axle per second, n, are connected with the radians turned through per second by the relation n =w/27r = w/6.38 (7) § 2. Methods of Applying Locomotive Power. - By locomotive power is to be understood the provision of power to maintain the rates of working on the driving-axles of a train indicated by the relation (4). The most usual way of providing this power is by the combustion of coal in the fire-box of a boiler and the utilization of the steam produced in a steam-engine, both boiler and engine being carried on a frame mounted on wheels in such a way that the crank-shaft of the steam-engine becomes the driving-axle of the train. From equation (3) it is clear that the wheels of the driving-axle must be heavily loaded in order that F may have a value sufficiently great to propel the train. The maximum weight which one pair of wheels are usually allowed to carry on a first-class track is from 18 to 20 tons. If a larger FIG. 16. - Wheel and Connexion to Frame.

value of the tractive force is required than this provides for, namely from 4 to 5 tons, the driving-wheels are coupled to one or more pairs of heavily loaded wheels, forming a class of what are called " coupled engines " in contradistinction to the " single engine " with a single pair of loaded driving-wheels. Mechanical energy may be developed in bulk at a central station conveniently situated with regard to a coal-field or a waterfall, and after transformation by means of electric generators into electric energy it may be transmitted to the locomotive and then by means of electric motors be retransformed into mechanical energy at the axles to which the motors are applied. Every axle of an electric locomotive may thus be subjected to a torque, and the large weight which must be put on one pair of wheels in order to secure sufficient adhesion when all the driving is done from one axle may be distributed through as many pairs of wheels as desired. In fact, there need be no specially differentiated locomotive at all. Motors may be applied to every axle in the train, and their individual torques adjusted to values suitable to the weights naturally carried by the several axles. Such an arrangement would be ideally perfect from the point of view of the permanent-way engineer, because it would then be possible to distribute the whole of the load uniformly between the wheels. This perfection of distribution is practically attained in present-day practice by the multiple control system of operating an electric train, where motors are applied to a selected number of axles in the train, all of them being under the perfect control of the driver.

The fundamental difference between the two methods is that while the mechanical energy developed by a steam engine is in the first case applied directly to the driving-axle of the locomotive, in the second case it is transformed into electrical energy, transmitted over relatively long distances, and retransformed into mechanical energy on the driving-axles of the train. In the first case all the driving is done on one or at most two axles, sufficient tractive force being obtained by coupling these axles when necessary to others carrying heavy loads. In the second case every axle in the train may be made a driving-axle if desired, in which case the locomotive as a separate machine disappears. In the second case, however, there are all the losses due to transmission from the central station to the train to be considered, as well as the cost of the transmitting apparatus itself. Ultimately the question resolves itself into one of commercial practicability. For suburban traffic with a service at a few minutes' interval and short distances between the stations electric traction has proved itself to be superior in many respects to the steam locomotive, but for main line traffic and long distance runs it has not yet been demonstrated that it is commercially feasible, though it is known to be practically possible. For the methods of electric traction see Traction; the remainder of the present article will be devoted to the steam locomotive.

§ 3. General Efficiency of Steam Locomotive. - One pound of good Welsh coal properly burned in the fire-box of a locomotive yields about 15,000 British thermal units of heat at a temperature high enough to enable from 50 to 80% to flow across the boiler-heating surface to the water, the rest escaping up the chimney with the furnace gases. The steam produced in consequence of this heat transference from the furnace gas to the water carries heat to the cylinder, where 7 to II % is transformed into mechanical energy, the remainder passing away up the chimney with the exhaust steam. The average value of the product of these percentages, namely o65 Xo09 =0.06 say, may be used to investigate generally the working of a locomotive; the actual value could only be determined by experiment in any particular case. With this assumption, 0.06 is the fraction of the heat energy of the coal which is utilized in the engine cylinders as mechanical work; that is to say, of the 15,000 B.Th.U. produced by the combustion of 1 lb of coal, 15,000 Xo06 =900 only are available for tractive purposes.

Coals vary much in calorific value, some producing only 12,000 B.Th.U. per lb when burnt, whilst 15,500 is obtained from the best Welsh coals. Let E represent the pounds of coal burnt per hour in the fire-box of a locomotive, and let c be the calorific value in B.Th.U. per lb; then the mechanical energy available in footpounds per hour is approximately 0-06 X 778 X Ec, and this expressed in horse-power units gives I.H.P. - o06X778XEc _648.1,980,000.

A " perfect engine " receiving and rejecting steam at the same temperatures as the actual engine of the locomotive, would develop about twice this power, say 1400 I.H.P. This figure represents the ideal but unattainable standard of performance. This question of the standard engine of comparison, and the engine efficiency is considered in § 15 below, and the boiler efficiency in § It below.

The indicated horse-power developed by a cylinder may always be ascertained from an indicator diagram and observations of the speed. Let p be the mean pressure in pounds per square inch, calculated from an indicator diagram taken from a particular cylinder when the speed of the crank-shaft is n revolutions per second. Also let l be the length of the stroke in feet and let a be the area of one cylinder in square inches, then, assuming two cylinders of equal size, I.H.P. =2 planl550 (8) The I.H.P. at any instant is equal to the total rate at which energy is required to overcome the tractive resistance R. The horsepower available at the driving-axle, conveniently called the brake horse-power, is from 20 to 30% less than the indicated horse-power, and the ratio, B.H.P./I.H.P. =E, is called the mechanical efficiency of the steam engine. The relation between the b.h.p. and the torque on the driving-axle is 55 o B.H.P. =Tu., (9) It is usual with steam locomotives to regard the resistance R as including the frictional resistances between the cylinders and the driving-axle, so that the rate at which energy is expended in moving the train is expressed either by the product RV, or by the value of the indicated horse-power, the relation between them being 55 0 I.H.P. =RV (Io) or in terms of the torque 55 0 I.H.P.X€=RVe=TW (II) The individual factors of the product RV may have any value consistent with equation (to) and with certain practical conditions, so that for a given value of the I.H.P. R must decrease if V increases. Thus if the maximum horse-power which a locomotive can develop is woo, the tractive resistance R, at 60 m. per hour (=88 ft. per second) is R = (woo X550)/88 =6250 lb. If, however, the speed is reduced to 15 m. per hour (= 22 ft. per second) R increases to 25,000 lb. Thus an engine working at maximum power may be used to haul a relatively light load at a high speed or a heavy load at a slow speed.

§ 4. Analysis of Train Resistance. - Train resistance may be analysed into the following components: (i) Journal friction and friction of engine machinery.

(2) Wind resistance.

(3) Resistance due to gradients, represented by R9. (4) Resistance due to miscellaneous causes.

(5) Resistance due to acceleration, represented by Ra. (6) Resistance due to curves.

The sum of all these components of resistance is at any instant equal to the resistance represented by R. At a uniform speed on a level straight road 3, 5 and 6 are zero. The total resistance is conveniently divided into two parts: (1) the resistance due to the vehicles hauled by the engine, represented by R q ; (2) the resistance of the engine and tender represented by R 4. In each of these two cases the resistance can of course be analysed into the six components set out in the above list.

§ 5. Vehicle Resistance and Draw-bar Pull. - The power of the engine is applied to the vehicles through the draw-bar, so that the draw-bar pull is a measure of the vehicle resistance. The draw-bar pull for a given load is a function of the speed of the train, and numerous experiments have been made to find the relation connecting the pull with the speed under various conditions. The usual way of experimenting is to put a dynamometer car (see Dynamometer) between the engine and the train. This car is equipped with apparatus by means of which a continuous record of the draw-bar pull is obtained on a distance base; time indications are also made on the diagram from which the speed at any instant can be deduced. The pull recorded on the diagram includes the resistances due to acceleration and to the gradient on which the train is moving. It is usual to subtract these resistances from the observed pull, so as to obtain the draw-bar pull reduced to what it would be at a uniform speed on the level. This corrected pull is then divided by the weight of the vehicles hauled, in which must be included the weight of the dynamometer car, and the quotient gives the resistance per ton of load hauled at a certain uniform speed on a straight and level road. A series of experiments were made by J. A. F. Aspinall on the Lancashire & Yorkshire railway to ascertain the resistance of trains of bogie passenger carriages of different lengths at varying speeds, and the results are recorded in a paper, " Train Resistance," Proc. Inst. C.E. (1901), vol. 147. Aspinall's results are expressed by the formula S 5+ 50.8 12 r„ =2 -}-00278,L where r ro is the resistance in pounds per ton, S is the speed in miles per hour, and L is the length of the train in feet measured over the carriage bodies. The two following expressions are given in the Bulletin of the International Railway Congress (vol. xii. p. 1275), by Barbier, for some experiments made on the Northern railway of France with a train of 157 tons mean weight; they are valid between 37 and 77 m. per hour: - rv= 3.58-I 165S(I 61S } 50) for 4-wheel coaches, (13) 1000 rv= 3-58+ I 645(1 61S +IO) for bogie coaches. 1000 The Baldwin Locomotive Company give the formulae 0.565 r =3.36+ 3 and r z ,= 1.68 +0.2245 for speeds from 47 to 77 m. per hour. (16) All the above formulae refer to carriage stock. The resistance of goods wagons has not been so systematically investigated. In the paper above quoted Aspinall cites a case where the resistance of a train of empty wagons 1830 ft. long was 18.33 lb per ton at a speed of 26 m. per hour, and a train of full wagons 1045 ft. long gave only 9.12 lb per ton at a speed of 29 m. per hour. The resistance found from the above expressions includes the components I, 2 and 4 of § 4. The resistance caused by the wind is very variable, and in extreme cases may double the resistance found from the formulae. A side wind causes excessive flange friction on the leeward side of the train, and increases the tractive resistances therefore very considerably, even though its velocity be relatively moderate. The curves corresponding to the above expressions are plotted in fig. 17, four values of L being taken for formula (12) corresponding to trains of 5, 10, 15 and 20 bogie carriages.

The resistance at starting is greater than the running resistance at moderate speeds. From Aspinall's experiments it appears to be about 17 lb per ton, and this value is plotted on the diagram.

The resistance to motion round a curve has not been so systematically studied that any definite rule can be formulated applicable to all classes of rolling stock and all radii of curves. A general result could not be obtained, even from a large number of experiments, because the resistance round curves depends upon so many variable factors. In some cases the gauge is laid a little wider than the standard, and there are varying amounts of superelevation of the outer rail; but the most formidable factor in the production of resistance is the guard-rail, which is sometimes put in with the object of guiding the wheel which runs on the inner rail of the curve on the inside of the flange.

From experiments made on the NorthEastern railway (see a paper by W. H. Smith on " Express Locomotive Engines," Proc. Inst. Mech. Eng., October 1898), it appeared that the engine resistance was about 35% of the total resistance, and in the train-resistance experiments on the Lancashire & Yorkshire railway quoted above the engine resistance was also about 35% of the total resistance, thus confirming the North-Eastern railway results. Barbier (loc. cit.) gives as the formula for the engine resistance re = 8.51 +3.24S(I. 61S+30)/Iooo (17) where S is the speed in miles per hour. This formula is valid between speeds of 37 and 77 m. per hour, and was obtained in connexion with the experiments previously quoted on the Northern railway of France with an engine and tender weighing about 83 tons. Barbier's formula is plotted in fig. 17, together with a curve expressing generally the results of some early experiments on the Great Western railway carried out by Sir D. Gooch. The extension of the Barbier curve beyond the above limits in fig. 17 gives values which must be regarded as only very approximate.

70 FIG. 17.

§ 7. Rate at which work is done against the resistances given by the curves fig. z7. - When the weight of the engine and tender and the weight of the vehicles are respectively given, the rate at which work must be done in the engine cylinders in order to maintain the train in motion at a stated speed can be computed by the aid of the curves plotted in fig. 17. Thus let an engine and tender weighing 80 tons haul vehicles weighing 200 tons at a uniform speed on the level of 40 m. per hour. As given by the Barbier curves in fig. 17, the engine resistance at 40 m. per hour is 20 lb per ton, and the vehicle resistance 8.5 lb per ton at the same speed. Hence Engine resistance, R e = 80 X20 = 1600 lb Vehicle resistance, R v =200 X8.5 = 1700 „ Train resistance, R = 3300 „ The speed, 40 m. per hour, is equal to 58.6 ft. per second; therefore the rate of working in foot-pounds per second is 3300 X58.6, from which I.H.P. _ (3300 X58.6)/550 = 354. This is the horse-power, therefore, which must be developed in the cylinders to maintain the train in motion at a uniform speed of 40 m. per hour on a level straight road with the values of the resistances assumed.

§ 8. Rate at which work is done against a gradient. - Gradients are measured either by stating the number of feet horizontally, G say, in which the vertical rise is I ft., or by the vertical rise in too ft. measured horizontally expressed as a percentage, or by the number of feet rising vertically in a mile. Thus a gradient of I in 200 is the same as a half per cent. grade or a rise of 26.4 ft. per mile. The difference between the horizontal distance and the distance measured along the rail is so small that it is negligible in all practical calculations. Hence if a train is travelling up the gradient at a speed of V ft. per second, the vertical rise per second is V/G ft. If W I is the weight of the train in pounds, the rate of working against the gradient expressed in horse-power units is H.P.=W,V/550 G. (18) Assuming the data of the previous section, and in addition that the train is required to maintain a speed of 40 m. per hour up a gradient of I in 300, the extra horse-power required will be H.P. _280X2240X58.6 =22 300 X 550 3.

This must be exerted in addition to the horse-power calculated in the previous section, so that the total indicated horse-power which must be developed in the cylinders is now 354+223 =577. If the train is running down a gradient this horse-power is the rate at which gravity is working on the train, so that with the data of the previous section, on the assumption that the train is running down a gradient of I in 300, the horse-power required to maintain the speed would be 354-223=131.

Rate at which work is done against acceleration. - If W 1 is the weight of the train in pounds and a the acceleration in feet per second, the force required to produce the acceleration is f = Wi a / g (19) And if V is the average speed during the change of velocity implied by the uniform acceleration a, the rate at which work is done by this force is fV= W1Va /g (20) or in horse-power units Time occupied in the change - 13 - 0 113. Therefore the horse-power which must be developed in the cylinders to effect this change of speed is from (21) H.P.280X2240X0113X59 = _237 55 0 X 32 The rate of working is negative when the train is retarded; for instance, if the train had changed its speed from 41 to 40 m. per hour in 13 seconds, the rate at which work would have to be absorbed by the brake blocks would represent 237 H.P. This is lost in heat produced by the friction between the brake blocks and the wheels, though in some systems of electric driving some of the energy stored in the train may be returned to the central station during retardation. The principal condition operating in the design of locomotives intended for local services with frequent stops is the degree of acceleration required, the aim of the designer being to produce an engine which shall be able to bring the train to its journey speed in the shortest time possible. For example, suppose it is required to start a train weighing 200 tons from rest and bring it to a speed of 30 m. per hour in 30 seconds. The weight of the engine may be assumed in advance to be 80 tons. The acceleration, a, which may be supposed uniform, is 1.465. The average velocity is 15 m. per hour, which is equal to 22 ft. per second; therefore the tractive force required is, from (19), (280 X2240XI. 465)/32 = 28,720 ib, and the corresponding horse-power which must be developed in the cylinders is, from (20), f V/550, and this is with f and V equal to the above values, 1149. To obtain the tractive force the weight on the coupled wheels must be about five times this amount - that is..

- 20 ton Speed in Miles per Hour 30 40 50 60 90 100 H.P. = W, Va /55 og (21) Assuming the data of § 7, suppose the train to change its speed from 40 to 41 m. per hour in 13 seconds. The average acceleration in feet per second is measured by the fraction Change of speed in feet per sec. 60.07-58.6 64 tons; and to obtain the horse-power the boiler will be one of the largest that can be built to the construction gauge. After acceleration to the journey speed of 30 m. per hour the horse-power required is reduced to about one-third of that required for acceleration alone.

§ 10. General expression for total rate of working. - Adding the various rates of working together R. H.P. - (Were ?-W v r v)V ?2240WV ?2240WVa (22) 55 0 550 550G 550g where W e is weight of engine and tender in tons, Wv the weight of vehicles in tons, W the weight of train in tons =W e r e and r z , the respective engine and vehicle resistances taken from the curves fig. 17 at a speed corresponding to the average speed during the acceleration a, G the gradient, g the acceleration due to gravity, and V the velocity of the train in feet per second. In this expression it is assumed that the acceleration is uniform, and this assumption is sufficiently accurate for any practical purpose to which the above formula would be applieu in the ordinary working of a locomotive. If a is variable, then the formula must be applied in a series of steps, each step corresponding to a time interval over which the acceleration may be assumed uniform.

Dividing thr Hugh by V and multiplying through by 550, 2240W 2240Wa R =Were+W vry t G (23) ' 'an expression giving the value of R the total tractive resistance. If the draw-bar pull is known to be R v, then applying the same principles to the vehicle alone which above are applied to the whole train, total draw-bar pull = Wvry 2240Wv 2240Wva. (24) G g This expression may be used to find r„ when the total draw-bar pull is observed as well as the speed, the changes of speed and the gradient. The speed held to correspond with the resistance must be the mean speed during the change of speed. The best way of deducing r„ is to select portions of the dynamometer record where the speed is constant. Then a disappears from all the above expressions. These expressions indicate what frequent changes in the power are required as the train pursues its journey up and down gradients, against wind resistance, j ournal friction and perhaps the resistance of a badly laid track; and show how both the potential energy and kinetic energy of the train are continually changing: the first from a change in vertical position due to the gradients, the second from changes in speed. These considerations also indicate what a difficult matter it is to find the exact rate of working against the resistances, because of the difficulty of securing conditions which eliminate the effect both of the gradient and of acceleration.

Maximum Power. - The maximum power which can be developed by a locomotive depends upon the maximum rate of fuel combustion which can be maintained per square foot of grate. This maximum rate depends upon the kind of coal used, whether small, friable, bituminous or hard, upon the thickness of the fire, and upon the correct design and setting of the blast-pipe. A limit is reached to the rate of combustion when the draught becomes strong. enough to carry heavy lighted sparks through the tubes and chimney. This, besides reducing the efficiency of the furnace, introduces the danger of fire to crops and buildings near the line. The maximum rate of combustion may be as much as so lb of coal per square foot of grate per hour, and in exceptional cases even a greater rate than this has been maintained. It is not economical to force the boiler to work at too high a rate, because it has been practically demonstrated that the boiler efficiency decreases after a certain point, as the rate of combustion increases. A few experimental results are set forth in Table XX., from which it will be seen that with a relatively low rate of combustion, a rate which denotes very light service, namely lb of coal per square foot of grate per hour, the efficiency of the boiler is %, which is as good a result as can be obtained with the best class of stationary boiler or marine boiler even when using economizers.

The first group consists of experiments selected from the records of a large number made on the boiler of the locomotive belonging to the Purdue University, Indiana, U.S.A.

The second group consists of experiments made on a boiler belonging to the Great Eastern Railway Company. The first one of the group was made on the boiler fixed in the locomotive yard at Stratford, and the two remaining experiments of the group were made while the engine was working a train between London and March.

The third group consists of experiments selected from the records of a series of trials made on the London & South-Western railway with an express locomotive.

§ 12. Draught. - One pound of coal requires about 20 lb of air for its proper combustion in the fire-box of a locomotive, though this quantity of air diminishes as the rate of combustion increases.

For instance, an engine having a grate area of 30 sq. ft. and burning too lb of coal per square foot of grate per hour would Table Xx require that 60,000 ib of air should be drawn through the furnace per hour in order to burn the coal. This large quantity of air is forced through the furnace by means of the difference of pressure established between the external atmospheric pressure in the ash-pan and the pressure in the smoke-box.

FIG. 18. - Smoke-box, L. & N.W.R. four-coupled 6 ft. 6 in. passenger engine, scale 24.

The exhaust steam passing from the engine through the blastpipe and the chimney produces a diminution of pressure, or partial vacuum, in the smoke-box roughly proportional to the weight of steam discharged per unit of time. The difference of pressure between the outside air and the smoke-box gases may be measured by the difference of the water levels in the limbs of a U tube, one limb being in communication with the smokebox, the other with the atmosphere. The difference of levels varies from r to as much as 10 in. in extreme cases. The draught corresponding to the smallest rate of combustion shown in Table XX. in Professor Goss's experiments, was 172 in. of water, and for the highest rate, namely 181, 7.48 in. of water. To get the best effect the area of the blast-nozzle must be properly proportioned to the size of the cylinders and be properly set with regard to the base of the chimney. The best proportions are found by trial in all cases.

Figs. 18 and 19 show two smoke-boxes typical of English practice. Fig. 18 is the smoke-box of the 6 ft. 6 in. six-coupled express passenger engines designed by G. Whale for the London & North-Western Railway Company in 1904, and fig. 19 shows the box of the fourcoupled express passenger engine designed by J. Holden for the FIG. lg. - Smoke-box and Spark Arrester, G.E.R. four-coupled express engine, scale A.

Great Eastern Railway Company. In the case of the London & North-Western engine (fig. 18), the blast-pipe orifice B is placed at about the centre of the boiler barrel, and the exhaust steam is discharged straight into the trumpet-shaped end of the chimney, which is continued down inside the smoke-box. In fig. 19 the blast orifice B is set much lower, and the steam is discharged through a frustum of a cone set in the upper part of the smoke-box into the short chimney. Fig. 20 shows the standard proportions recommended - by the committee of the Railway Mas * ter Mechanics' Association on Exhaust _ Pipes and Steam Passages (Prot. Amer. Railway Master Mechanics' Assoc., Ig06).

D According to the Report, for the best results both H and h should be made as great as practicable, and then d= o21D-l-o16h, b=2d or o. 5D, P=o32D, p=o22D, L=o6D or o9D, but not of intermediate values. This last relation is, however, not well established. For much detailed information regarding American smoke-box practice, reference may be made to Locomotive Sparks, by Professor W. F. M. Goss (London, 1902). The arrangements for arresting sparks in American practice and on the continent of Europe are somewhat elaborate. In English practice where a spark-arrester is put in it usually takes the form of a wire-netting dividing the smoke-box horizontally into two parts at a level just above the top row of tubes, or arranged to form a continuous connexion between the blast-pipe and the chimney.

Fig. 19 illustrates an arrangement designed by J. Holden. The heavy sparks are projected from the tubes in straight lines and are caught by the louvres L, L, L, and by them deflected downwards to the bottom of the smoke-box, where they collect in a heap in the space D round a tube which is essentially an ejector. At every blast a small quantity of steam is caught by the orifice 0 and led to the ejectors, one on each side, with the result that the ashes are blown out into the receptacles on each side of the engine, one of which is shown at E. The louvres 1, 1, l are placed to shield the central region occupied by the blast-pipe.

As the indicated horse-power of the engine increases, the weight of steam discharged increases, and the smoke-Lox vacuum is increased, thereby causing more air to flow through the furnace and increasing the rate of combustion. 'I hus the demand for more steam is automatically responded to by the boiler. It is this close automatic interdependence cf engir e and boiler which makes the locomotive so extraordinarily w ell suited for the purpose of locomotive traction.

The steam engine of a locomotive has the general characteristics of a double-acting non-condensing engine (see Steam Engine). Distribution of steam is effected by a slide valve, sometimes fitted with a balancing device, and sometimes formed into a piston valve. All types of valves are with few exceptions operated by a link motion, generally of the Stephenson type, occasionally of the Allan type or the Gooch type, or with some form of radial gear as the Joy gear or the Walschaert gear, though the latter gear has characteristics which ally it with the link motions. The Stephenson link motion is used almost universally in England and America, but it has gradually been displaced by the Walschaert gear on the continent of Europe, and to some extent in England by the Joy gear. The general characteristics of the distribution effected by these gears are similar. Each of them, besides being a reversing gear, is an expansion gear both in forward and backward running. The lead is variable in the Stephenson link motion, whilst in the Walschaert and the Joy gears it is constant. Illustrations of these gears are given in the article Steam Engine, and the complete distribution of steam for both forward and backward running is worked out for a typical example of each of them in Valves and Valve Gear Z1 ecl.cnisms by W. E. Dalby (London, 1906).

Adhesion. - Tractive Fcrce. - A locomotive must be designed to fulfil two conditions. First, it must be able to exert a tractive force sufficient to start the train under the worst conditions possible on the railway over which it is to operate - for instance, when the train is stopped by signal on a rising gradient where the track is curved and fitted with a guard-rail. Secondly, it must be able to maintain the train at a given speed against the total resistances of the level or up a gradient of given inclination. 7 hose conditions are to a certain extent mutually antagonistic, since an engine designed to satisfy either condition independently of the other R euld Le a different engine from that designed to make the best ccmpromise between them.

Equation (3), § I expresses the fundamental condition which must be satisfied when a locomotive is starting a train. 7 he torque exerted on the driving-axle by the steam engine just at starting may be that due to the full boiler pressure acting in the cylinders, but usually the weight on the coupled wheels is hardly sufficient to enable advantage to be taken of the full boiler pressure, and it has to be throttled down by the regulator to prevent slipping. Sand, driven between the wheel and the rail by a steam jet, used just at starting, increases the adhesion beyond the normal value and enables a larger pressure to be exerted on the piston than would otherwise be possible. V hen the train is started and is moving slowly, the toroue acting on the driving-axle may be estimated as that due to about 85°/, of the full boiler pressure acting in the cylinders. The torque;?i H ti l ' --- L-- - -Tt FIG. 20. - Smoke-box, American Railway Master Mechanics' Association.

due to the two cylinders is variable to a greater or less extent, depending upon the degree of expansion in the cylinders and the speed. The form of the torque curve, or crank effort curve, as it is sometimes called, is discussed in the article Steam Engine, and the torque curve corresponding to actual indicator diagrams taken from an express passenger engine travelling at a speed of 65 m. per hour is given in The Balancing of Engines by W. E. Dalby (London, 1906).

The plotting of the torque curve is laborious, but the average torque acting, which is all that is required for the purposes of this article, can be found quite simply, thus: - Let p be the mean effective pressure acting in one cylinder, a, the area of the cylinder, and 1, the stroke. Then the work done during one revolution of the crank is 2pla per cylinder. Assuming that the mean pressure in the other cylinder is also p, the total work done per revolution is 4pla. If T is the mean torque, the work done on the crank-axle per revolution is 27rT. Hence assuming the mechanical efficiency of the engine to be and substituting ! d 2 for the area a, 4 27-T = 4 plae = plird2e, so that T = z pd2le. But from § I, T=2DF; therefore F = pd 2 lE/D (25) F in this expression is twice the average magnitude of the equal and opposite forces constituting the couple for one driving-wheel illustrated in fig. 16, one force of which acts to propel the train whilst the other is the value of the tangential frictional resistance between the wheel and the rail. This force F must not exceed the value. V or slipping will take place. Hence, if p is the maximum value of the mean effective pressure corresponding to about 85% of the boiler pressure, ,uW = pd 2 le /D (26) is an expression giving a relation between the total weight on the coupled wheels, their diameters and the size of the cylinder. The magnitude of F when p and e are put each equal to unity, is usually called the tractive force of the locomotive per pound of mean effective pressure in the cylinders. If p is the mean pressure at any speed the total tractive force which the engine is exerting is given by equation (25) above. The value of is variable, but is between 7 and 8, and for approximate calculations may be taken equal to unity. In the following examples the value will be assumed unity.

These relations may be illustrated by an example. Let an engine have two cylinders each 19 in. diameter and 26 in. stroke. Let the boiler pressure be 175 lb per square inch. Taking 85% of this, the maximum mean effective pressure would be 149 lb per square inch. Further, let the diameter of the driving-wheels be 6 ft. 3 in. Then the tractive force is, from (25), (149 X 19 2 X2.166)/6.25 =18,600lb =8.3 tons.

Assuming that the frictional resistance at the rails is given by the weight on the wheels, the total weight on the driving-wheels necessary to secure sufficient adhesion to prevent slipping must be at least 8.3 X5 =41.5 tons. This would be distributed between three coupled axles giving an average of 1.38 tons per axle, though the distribution might not in practice be uniform, a larger proportion of the weight falling on the driving-axle. If the starting resistance of the whole train be estimated at 16 lb per ton, this engine would be able to start 1.163 tons on the level, or about 400 tons on a gradient of I in 75, both these figures including the weight of the engine and tender, which would be about 100 tons.

The engine can only exert this large tractive force so long as the mean pressure is maintained at 149 lb per square inch. This high mean pressure cannot be maintained for long, because as the speed increases the demand for steam per unit of time increases, so that cut-off must take place earlier and earlier in the stroke, the limiting steady speed being attained when the rate at which steam is supplied to the cylinders is adjusted by the cut-off to be equal to the maximum rate at which the boiler can produce steam, which depends upon the maximum rate at which coal can be burnt per square foot of grate. If C is the number of pounds of coal burnt per square foot of grate per hour, the calorific value of which is c B.Th.U. per pound, the maximum indicated horse-power is given by the expression I.H.P. maximum - CcA X778 1980000 where A is the area of the grate in square feet, and is the combined efficiency of the engine and boiler. With the data of the previous example, and assuming in addition that the grate area is 24 sq. ft., that the rate of combustion is 150 lb of coal per square foot of grate per hour, that the calorific value is 14000, and finally that n =0.06, the maximum indicated horse-power which the engine might be expected to develop would be o06 X 150 x14000 X24 X 778/1980000 = I 190, corresponding to a mean effective pressure in the cylinders of 59.5 lb per square inch.

Assuming that the train is required to run at a speed of 60 m. per hour, that is 88 ft. per second, the total resistance R, which the engine can overcome at this s p eed, is by equation (10) R=(1190X550)/88=7.400 lb.

Thus although at a slow speed the engine can exert a tractive force of 18,600 lb, at 60 m. per hour, the tractive force falls to 7400 lb, and this cannot be increased except by increasing the rate of combustion (neglecting any small changes due to a change in the efficiency 7 Knowing the magnitude of R, the draw-bar pull, and hence the weight of vehicle the engine can haul at this speed, can be estimated if the resistances are known. Using the curves of fig. 17 it will be found that at 60 m. per hour the resistance of the engine and tender is 33 lb per ton, and the resistance of a train of bogie coaches about 14 lb per ton. Hence if W is the weight of the vehicles in tons, and the weight of the engine and tender be taken at too tons, the value of W can be found from the equation 1 4 W +33 00= 744 0, from which W =296 tons. This is the load which the engine would take in ordinary weather. With exceptionally bad weather the load would have to be reduced or two engines would have to be employed, or an exceptionally high rate of combustion would have to be maintained in the fire-box.

It will be seen at once that with a tractive force of 7400 lb a weight of 37,000 lb (=16.5 tons) would be enough to secure sufficient adhesion, and this could be easily carried on one axle. Hence for a level road the above load could be hauled at 60 m. per hour with a " single " engine. When the road leads the train up an incline, however, the tractive force must be increased, so that the need for coupled wheels soon arises if the road is at all a heavy one.

§15. Engine Efficiency. Combined Engine and Boiler Efficiency. - The combined engine and boiler efficiency has hitherto been taken to be o06; actual values of the boiler efficiencies are given in Table XX. Engine efficiency depends upon many variable factors, such as the cut-off, the piston speed, the initial temperature of the steam, the final temperature of the steam, the quality of the steam, the sizes of the steam-pipes, ports and passages, the arrangement of the cylinders and its effect on condensation, the mechanical perfection of the steam-distributing gear, the tightness of the piston, &c. A few values of the thermal efficiency obtained from experiments are given in Table XXI. in the second column, the first column being added to give some idea of the rate at which the engine was working when the data from which the efficiency has been deduced were observed. The corresponding boiler efficiencies are given in the third column of the table, when they are known, and the combined efficiencies in the fourth column. The figures in this column indicate that o06 is a good average value to work with.

Table Xxi It is instructive to inquire into the limiting efficiency of an engine consistent with the conditions under which it is working, because in no case can the efficiency of a steam-engine exceed a certain value which depends upon the temperatures at which it receives and rejects heat. Thus a standard of comparison for every individual engine may be obtained with which to compare its actual performance. The standard of comparison generally adopted for this purpose is obtained by calculating the efficiency of an engine working according to the Rankine cycle. That is to say, expansion is adiabatic and is continued down to the back pressure which in a non-condensing engine is 14.7 lb per square inch, since any back pressure above this amount is an imperfection which belongs to the actual engine. The back pressure is supposed to be uniform, and there is no compression.

Fig. 21 shows the pressure-volume diagram of the Rankine cycle for one pound of steam where the initial pressure is 175 lb per square inch by the 19t, gauge, equivalent to 190 lb per square inch absolute. In no case could an engine receiving steam at the tem perature corresponding to this pressure and rejecting heat at 212° F. convert more heat into work than is represented by the area of this diagram. The area of the diagram may be measured, but it is usually more convenient to calculate the number of B.Th.U. which the area represents from the following formula, which is expressed in terms of the absolute temperature T, of the steam at the steam-pipe, and the temperature T2= 461°H-212° =673° absolute corresponding to the back pressure: - Maximu per pound oflsteaelwork =U=(T - T) (i -f -Lr--.1) - T2loge.Tr--2.

With the initial pressure of 190 11; per square inch absolute it will be found from a steam table that T =838° absolute. Using this and the temperature 673° in the expression, it will be found that U =185 B.Th.U. per pound of steam. If h is the water heat at the lower temperature, h l the water heat at the higher temperature, and L the latent heat at the higher temperature, the heat supply per pound of steam is equal to h1 - h2+L1, which, from the steam tables, with the values of the temperatures given, is equal to 1013 B.Th.U. per pound. The thermal efficiency is therefore 185/1013 =0.183.

That is to say, a perfect engine working between the limits of temperature assigned would convert only 18% of the total heat supply into work. This would be an ideal performance for an engine receiving steam at 190 lb initial pressure absolute, and rejecting steam at the back pressure assumed above, and could never be attained in practice. When the initial pressure is 100 lb per square inch by the gauge the thermal efficiency drops to about nearly 15% with the same back pressure. The way the thermal efficiency of the ideal engine increases with the pressure is exhibited in fig. 22 by the curve AB. The curve was drawn by calculating the thermal efficiency from the above expression for various values of the initial temperature, keeping the final temperature constant at 673°, and then plotting these efficiencies against the corresponding values of the gauge pressures.

The actual thermal efficiencies observed in some of the cases cited in Table XXI. are plotted on the diagram, the reference numbers on which refer to the first column in the table. Thus the Fio. 22. - Engine Efficiency Curves.

cross marked 3 in fig. 22 represents the thermal efficiency actually obtained in one of Adams and Pettigrew's experiments, namely, 0-I I, the pressure in the steam-pipe being 167 lb per square inch. From the diagram it will be seen that the corresponding efficiency of the ideal engine is about 0.18. The efficiency ratio is therefore o11 /o. 18 =0.61. That is to say, the engine actually utilized 61% of the energy which it was possible to utilize by means of a perfect engine working with the same initial pressure against a back pressure equal to;the atmosphere. Lines representing efficiency ratios of o6, 0.5 and 0.4 are plotted on the diagram, so that the efficiency ratios corresponding to the various experiments plotted may be readily read off. The initial temperature of the standard engine of comparison must be the temperature of the steam taken in the steam-pipe. For further information regarding the standard engine of comparison see the article Steam Engine and also the " Report of the Committee on the Thermal Efficiency of Steam Engines," Proc. Inst. C.E. (1898).

The expression for the indicated horse-power may be written I.H.P. =pay/550 (27) where v is the average piston speed in feet per second. For a stated value of the boiler pressure and the cut-off the mean pressure p is a function of the piston speed v. For the few cases where data are available - data, however, belonging to engines representing standard practice in their construction and in the design of cylinders and steam ports and passages - the law connecting p and v is approximately linear and of the form p=c - bv (28) where b and c are constants. (See W. E. Dalby, " The Economical Working of Locomotives," Proc. Inst. C.E., 1905-6, vol. 164.) Substituting this value of p in (27) I.H.P. _ (c av (29) 550 the form of which indicates that there is a certain piston speed for which the I.H.P. is a maximum. In a particular case where the boiler pressure was maintained constant at 130 lb per square inch, and the cut-off was approximately 20% of the stroke, the values c =55 and b=o031 were deduced, from which it will be found that the value of the piston speed corresponding to the maximum horsepower is 887 ft. per minute. The data from which this result is deduced will be found in Professor Goss's paper quoted above in Table XXI. The point is further illustrated by some curves published in the American Engineer (June 1901) by G. R. Henderson recording the tests of a freight locomotive made on the Chicago & North-Western railway. Any modification of the design which will reduce the resistance to the flow of steam through the steam passages at high speeds will increase the piston speed for which the indicated horse-power is a maximum.

The thermal efficiency of a steam-engine is in general increased by carrying out the expansion of the steam in two, three or even more stages in separate cylinders, notwithstanding the inevitable drop of pressure which must occur when the steam is transferred from one cylinder to the other during the process of expansion. Compound working permits of a greater range of expansion than is possible with a simple engine, and incidentally there is less range of pressure per cylinder, so that the pressures and temperatures per cylinder have not such a wide range of variation. In compound working the combined volumes of the low-pressure cylinders is a measure of the power of the engine, since this represents the final volume of the steam used per stroke. The volume of the high-pressure cylinder may be varied within wide limits for the same low-pressure volume; the proportions adopted should, however, be such that there is an absence of excessive drop between them as the steam is transferred from one to the other. Compound locomotives have been built by various designers, but opinion is still uncertain whether any commercial economy is obtained by their use. The varying load against which a locomotive works, and the fact that a locomotive is non-condensing, are factors which reduce the margin of possible economy within narrow limits. Coal-saving can be shown to the extent of about 1% in some cases, but the saving depends upon the kind of service on which the engine is employed. The first true compound locomotive was constructed in 1876 from designs by A. M. Mallet, at the Creusot works in Bayonne. The first true compound locomotive in England was constructed at Crewe works in 1878 by F. W. Webb. It was of the same type as Mallet's engine, and was made by simply bushing one cylinder of an ordinary two-cylinder simple engine, the bushed cylinder being the high-pressure and the other cylinder the low-pressure cylinder. Webb evolved the type of threec y linder compound with which his name is associated in 1882.

020 610 3 30 140 150 160 170 180 190 200 210 220 230 240 250 260 Area is Equivalent to 185 8. Thar equal to 148930 foot pounds 4 2.37 cubic feet. Indicator diagram corresponding to 1 lb. of steam for the Rankine Engine of Comparison when is 190 lbs sq. inch absolute, and exhaust pressis lbs sq. inch absolute There were two high-pressure cylinders placed outside the frames and driving on a trailing wheel, and one low-pressure cylinder placed between the frames and driving on a wheel placed in front of the driving-wheel belonging to the highpressure cylinders. The steam connexions were such that the two high-pressure cylinders were placed in parallel, both exhausting into the one low-pressure cylinder. The first engines of this class were provided with high-pressure cylinders, i i in. diameter and 24 in. stroke, a low-pressure cylinder 26 in. diameter, 24 in. stroke, and driving-wheels 6 ft. 6 in. diameter; but subsequently these dimensions were varied. There were no coupling rods. A complete account of Webb's engines will befound in a paper, " The Compound Principle applied to Locomotives," by E. Worthington, Proc. Inst. C.E., 1889, vol. xcvi. Locomotives have to start with the full load on the engine, consequently an outstanding feature of every compound locomotive is the apparatus or mechanism added to enable the engine to start readily. Generally steam from the boiler is admitted direct to the low-pressure cylinder through a reducing valve, and valves and devices are used to prevent the steam so admitted acting as a back pressure on the high-pressure cylinder. In the Webb compound the driver opened communication from the high-pressure exhaust pipe to the blast-pipe, and at the same time opened a valve giving a supply of steam from the boiler direct to the lowpressure valve chest. T. W. Worsdell developed the design of the two-cylinder compound in England and built several, first for the Great Eastern railway and subsequently for the North-Eastern railway. The engines were built on the Worsdell and Von Borries plan, and were fitted with an ingenious startingvalve of an automatic character to overcome the difficulties of starting. Several compounds of a type introduced by W. M. Smith on the North-Eastern railway in 1898 have been built by the Midland railway. In these there are two lowpressure cylinders placed outside the frame, and one highpressure cylinder placed between the frames. All cylinders drive on one crank-axle with three cranks at 120°. The drivingwheels are coupled to a pair of trailing wheels. A controlling valve enables the supply of steam to the low-pressure cylinders to be supplemented by boiler steam at a reduced pressure. For a description and illustrations of the details of the starting devices used in the Webb, Worsdell and Smith compounds, see an article, " The Development of the Compound Locomotive in England," by W. E. Dalby in the Engineering Magazine for September and October 1904. A famous type of compound locomotive developed on the continent of Europe is the four-cylinder De Glehn, some of which have been tried on the Great Western railway. There are two high-pressure cylinders placed outside the frame, and two low-pressure placed inside the frames. The low-pressure cylinders drive on the leading crank-axle with cranks at right angles, the highpressure cylinders driving on the trailing wheels. The wheels are coupled, but the feature of the engine is that the couplingrods act merely to keep the high-pressure and low-pressure engines in phase with one another, very little demand being made upon them to transmit force except when one of the wheels begins to slip. In this arrangement the whole of the adhesive weight of the engine is used in the best possible manner, and the driving of the train is practically equally divided between two axles. The engine can be worked as a four-cylinder simple at the will of the driver. S. M. Vauclain introduced a successful type of four-cylinder compound in America in 1889. A highand low-pressure cylinder are cast together, and the piston-rods belonging to them are both coupled to one cross-head which is connected to the driving-wheels, these again being coupled to other wheels in the usual way. The distribution of steam to both cylinders is effected by one piston-valve operated by a link motion, so that there is considerable mechanical simplicity in the arrangement. Later Vauclain introduced the " balanced compound." In this engine the two piston-rods of one side are not coupled to a common cross-head, but drive on separate cranks at an angle of 180°, the pair of 180° cranks on each side being placed at right angles.

The unbalanced masses of a locomotive may be divided into two parts, namely, masses which revolve, as the crank-pins, the crank-cheeks, the couplingrods, &c.; and masses which reciprocate, made up of the piston, piston-rod, cross-head and a certain proportion of the connecting-rod. The revolving masses are truly balanced by balance weights placed between ' the spokes of the wheels, or sometimes by prolonging the crank-webs and forming the prolongation into balance weights. It is also the custom to balance a proportion of the reciprocating masses by balance weights placed between the spokes of the wheels, and the actual balance weight seen in a driving-wheel is the resultant of the separate weights required for the balancing of the revolving parts and the reciprocating parts. The component of a balance weight which is necessary to balance the reciprocating masses introduces a vertical unbalanced force which appears as a variation of pressure between the wheel and the rail, technically called the hammer-blow, the magnitude of which increases as the square of the speed of the train. In consequence of this action the compromise is usually followed of balancing only 3 of the reciprocating masses, thus keeping the hammer-blow within proper limits, and allowing 3 of the reciprocating masses to be unbalanced in the horizontal direction. It is not possible to do anything better with two-cylinder locomotives unless bobweights be added, but with four-cylinder four-crank engines complete balance is possible both in the vertical and in the horizontal directions. When the four cranks are placed with two pairs at 180°, the pairs being at 90°, the forces are balanced without the introduction of a hammer-blow, but there remain large unbalanced couples, which if balanced by means of revolving weights in the wheels again reintroduce the hammerblow, and if left unbalanced tend to make the engine oscillate in a horizontal plane at high speed. The principles by means of which the magnitude and position of balance weights are worked out are given in the article Mechanics (Applied Mechanics), and the whole subject of locomotive balancing is exhaustively treated with numerous numerical examples in The Balancing of Engines by W. E. Dalby, London, 1906.

Locomotives may be classified primarily into " tender engines " and " tank engines," the water and fuel in the latter being carried on the engine proper, while in the former they are carried in a separate vehicle. A tender is generally mounted on six wheels, or in some cases on two bogies, and carries a larger supply of water and fuel than can be carried by tanks and the bunker of a tank engine. A tender, however, is so much dead-weight to be hauled, whilst the weight of the water and fuel in a tank engine contributes largely to the production of adhesion. A classification may also be made, according to the work for which engines are designed, into passenger engines, goods engines, and shunting or switching engines. A convenient way of describing any type of engine is by means of numerals indicating the number of wheels - (I) in the group of wheels supporting the leading or chimney end, (2) in the group of coupled wheels, and (3) in the group supporting the trailing end of the engine. In the case where either the leading or trailing group of small wheels is absent the numeral o must be used in the series of three numbers used in the description. Thus 4-4-2 represents a bogie engine with four-coupled wheels and one pair of trailing wheels, the wellknown Atlantic type; 4-2-2 represents a bogie engine with a single pair of driving-wheels and a pair of trailing wheels; 0-4-4 represents an engine with four-coupled wheels and a trailing bogie, and 4-4-o an engine with four-coupled wheels and a leading bogie. A general description of the chief peculiarities of various kinds of locomotives is given in the following analysis of types: (I) " Single-driver " type, 4-2-2 or 2-2-2. Still used by several railways in Great Britain for express passenger service, but going out of favour; it is also found in France, and less often in Germany, Italy, and elsewhere in Europe. It is generally designed as a 4-2-2 engine, but some old types are still running with only three axles, the 2-2-2. It is adapted for light, high-speed service, and noted for its simplicity, excellent riding qualities, low cost of maintenance, and high mechanical efficiency; but having limited adhesive weight it is unsuitable for starting and accelerating heavy trains.

(2) " Four-coupled " type, 4-4-0, with leading bogie truck. For many years this was practically the only one used in America for all traffic, and it is often spoken of as the " American " type. In America it is still the standard engine for passenger traffic, but for goods service it is now employed only on branch lines. It has been extensively introduced, both in Great Britain and the continent of Europe, for passenger traffic, and is now the most numerous and popular class. It is a safe, steady-running and trustworthy engine, with excellent distribution of weight, and it is susceptible of a wide range of adaptability in power requirements.

(3) " Four-coupled " three-axle type, 2-4-0. Used to some extent in France and Germany and considerably in England for passenger traffic of moderate weight. Engines of this class, with 78-inch driving wheels and the leading axle fitted with Webb's radial axle-box, for many years did excellent work on the London & North-Western railway. The famous engine " Charles Dickens " was one of this class. Built in 1882, it had by the 12th of September 1891 performed the feat of running a million miles in 9 years 219 days, and it completed two million miles on the 5th of August 1902, having by that date run 5312 trips with express trains between London and Manchester.

(4) " Four-coupled " three-axle type, with trailing axle, 0-4-2. Used on several English lines for fast passenger traffic, and also on many European railways. The advantages claimed for it are: short coupling-rods, large and unlimited fire-box carried by a trailing axle, compactness, and great power for a given weight. Its critics, however, accuse it of lack of stability, and assert that the use of large leading wheels as drivers results in rigidity and produces destructive strains on the machinery and permanent way.

(5) " Four-coupled " type, with a leading bogie truck and a trailing axle, 4-4-2. It is used to a limited extent both in England and on the continent of Europe, and is rapidly increasing in favour in the United States, where it originated and is known as the " Atlantic " type. It has many advantages for heavy high-speed service, namely, large and well-proportioned boiler, practically unlimited grate area, fire-box of favourable proportions for firing, fairly low centre of gravity, short coupling-rods, and, finally, a combination of the safe and smooth riding qualities of the fourcoupled bogie type, with great steaming capacity and moderate axle loads. Occasionally a somewhat similar type is designed with the bogie under the fire-box and a single leading axle forward under the smoke-box - an arrangement in favour for suburban tank engines. In still rarer cases both a leading and a trailing bogie have been fitted.

(6) " Six-coupled " with bogie, or " Ten-wheel " type, 4-6-0. A powerful engine for heavy passenger and fast goods service. It is used to a limited extent both in Great Britain and on the continent of Europe, but is much more common in America. The design combines ample boiler capacity with large adhesive weight and moderate axle loads, but except on heavy gradients or for unusually large trains requiring engines of great adhesion, passenger traffic can be more efficiently and economically handled by four-coupled locomotives of the eight-wheel or Atlantic types.

(7) " Six-coupled " total-adhesion type (all the weight carried on the drivers), o-6-o. This is the standard goods engine of Great Britain and the continent of Europe. In America the type is used only for shunting. It is a simple design of moderate boiler power.

(8) " Six-coupled " type, with a leading axle, 2-6-0. This is of American origin, and is there known as the " Mogul." It is used largely in America for goods traffic. In Europe it is in considerable favour for goods andpassenger traffic on heavy gradients. The type is, however, less in favour than either the ten-wheel or the eight-coupled " Consolidation " for freight traffic.

(9) " Eight-coupled " total-adhesion type, o-8-o; now found on a good many English railways, and common on the continent of Europe for heavy slow goods traffic. In America it is comparatively infrequent, as total-adhesion types are not in favour.

(io) " Eight-coupled " type, with a leading axle, 2-8-0. This originated in America, where it is termed the " Consolidation." In the United States it is the standard heavy slow-speed freight engine, and has been built of enormous size and weight. The type has been introduced in Europe, especially in Germany, where the advantages of a partial-adhesion type in increased stability and a larger boiler are becoming appreciated. Occasionally the American eight-coupled type has a bogie instead of a single leading axle (4-8-0), and is then termed a " Twelve-wheeler," or " Mastodon." (11) " Ten-coupled " type, with a leading axle, 2-10-0. This originated in America, where it is known as the " Decapod." It is used to a limited extent for mountain-grade goods traffic, and has the advantage over the " Consolidation " or eight-coupled type of lighter axle loads for a given tractive capacity.

In addition to the foregoing list, various special locomotive types have been developed for suburban service, where high rates of acceleration and frequent stops are required. These are generally tank engines, carrying their fuel and water on the engine proper.

Their boilers are of relatively large proportions for the train weight and average speed, and the driving wheels of small diameter, a large proportion of their total weight being " adhesive." Other special types are in limited use for " rack-railways," and operate either by engagement of gearing on the locomotive into a rack between the track rails, or by a combination of this and rail adhesion.

§ 20. Current Developments. - The demand of the present day is for engines of larger power both for passenger and goods service, and the problem is to design such engines within the limitations fixed by the 4 ft. 82 in. gauge and the dimensions of the existing tunnels, arches, and other permanent works. The American engineer is more fortunately situated than his English brother with regard to the possibility of a solution, as will be seen from the comparative diagrams of construction gauges, figs. 23, 24, 25, 26. Fig. 23 shows the construction L.& N.W. Ry. FIGS. 23-26.

gauge for the London & North-Western railway, fig. 24 that for the Great Western' railway, fig. 25 that for the Great Eastern railway, whilst fig. 26 gives a general idea of the American gauge in a particular case, generally typical, however, of the American limits. In consequence of this increasing demand for power, higher boiler pressures are being used, in some cases 225 lb per sq. in. for a simple two-cylinder engine, and cylinder volume is slightly increased with the necessary accompaniment of heavier loads on the coupled wheels to give the necessary adhesion. Both load and speed have increased so much in connexion with passenger trains that it is necessary to divide the weight required for adhesion between three-coupled axles, and the type of engine gradually coming into use in England for heavy express traffic is a six-coupled engine with a leading bogie, with wheels which would have been considered small a few years ago for the speed at which the engine runs. The same remarks apply to goods engines. There is a general increase in cylinder power, boiler pressure and weight, and in consequence in the number of coupled axles. Not only are the load and speed increasing, but the distances run without a stop are increasing also, and to avoid increasing the size of the tenders, water-troughs, first instituted by J. Ramsbottom on the London & North-Western railway in 1859, have been laid in the tracks of the leading main lines of Great Britain. For local services where stoppages are frequent the demand is for engines capable of quickly ' At the beginning of 1908 the Great Western's loading gauge on its main lines was widened to 9 ft. 8 in. from a height of 5 ft. above rail level.

G.WI. Ry. Table Xxii. - Comparative Data Of Locomotives accelerating the train to the journey speed. The nature of this problem is illustrated by the numerical example in § g. When the service is frequent enough to give a good power factor continuously, the steam locomotive cannot compete with the electric motor for the purpose of quick acceleration, because the motors applied to the axles of a train may for a short time absorb power from the central station to an extent far in excess of anything which a locomotive boiler can supply.

With regard to the working of the locomotive, J. Holden developed the use of liquid fuel on the Great Eastern railway to a point beyond the experimental stage, and used it instead of coal with the engines running the heavy express traffic of the line, its continued use depending merely upon the relative market price of coal and oil. Compound locomotives have been tried, as stated in § 17, but the tendency in England is to revert to the simple engine for all classes of work, though on the continent of Europe and in America the compound locomotive is largely adopted, and is doing excellent work. A current development is the application of superheaters to locomotives, and the results obtained with them are exceedingly promising.

The leading dimensions of a few locomotives typical of English, American and European practice are given in Table Xxii. (W. E. D.) Rolling Stock The rolling stock of a railway comprises those vehicles by means of which it effects the transportation of persons and things over its lines. It may be divided into two classes, according as it is intended for passenger or for goods traffic.

In the United Kingdom, as in Europe generally, the vehicles used on passenger trains include firstclass carriages, second-class carriages, third-class carriages, composite carriages containing compartments for two or more classes of passengers, dining or restaurant carriages, sleeping carriages, mail carriages or travelling post offices, luggage brake vans, horse-boxes and carriage-trucks. Passenger carriages were originally modelled on the stage-coaches which they superseded, and they are often still referred to as " coaching stock." Early examples had bodies about 15 ft. long, 61 ft. wide and 44 ft. high; they weighed 3 or 4 tons, and were divided into three compartments holding six persons each, or eighteen in all.

The distinction into classes was made almost as soon as the railways began to carry passengers. Those who paid the highest fares (22d. or 3d. a mile) were provided with covered vehicles, on the roofs of which their luggage was carried, and from the circumstance that they could book seats in advance came the term " booking office," still commonly applied to the office where tickets are issued. Those who travelled at the cheaper rates had at the beginning to be content with open carriages having little or no protection from the weather. Gradually, however, the accommodation improved, and by the middle of the 19th century second-class passengers had begun to enjoy " good glass windows and cushions on the seat," the fares they paid being about 2d. a mile. But though by an act of 1844 the railways were obliged to run at least one train a day over their lines, by which the fares did not exceed the " Parliamentary " rate of id. a mile, third-class passengers paying 14 d. or 12 d. a mile had little consideration bestowed on their comfort, and were excluded from the fast trains till 1872, when the Midland railway admitted them to all its trains. Three years later that railway did away with second-class compartments and improved the third class to their level. This action had the effect, through the necessities of competition, of causing travellers in the cheaper classes to be better treated on other railways, and the condition of the third-class passenger was still further improved when Parliament, by the Cheap Trains Act of 1883, required the railways to provide " due and sufficient " train accommodation at fares not exceeding id. a mile. In the United Kingdom it is now possible to travel by every train, with very few exceptions, and in many cases to have the use of restaurant cars, for id. a mile or less, and the money obtained from third-class travellers forms by far the most important item in the revenue from passenger traffic. Since the Midland railway's action in 1875 several other English companies have abandoned second-class carriages either completely or in part, and in Scotland they are entirely unknown.

On the continent of Europe there are occasionally four classes, but though the local fares are often appreciably lower than in Great Britain, only first and second class, sometimes only first class, passengers are admitted to the fastest trains, for which in addition a considerable extra fare is often required. In Hungary and Russia a zone-tariff system is in operation, whereby the charge per mile decreases progressively with the length of the journey, the traveller paying according to the number of zones he has passed through and not simply according to the distance traversed. In the United States there is in most cases nominally only one class, denominated first class, and the average fare obtained by the railways is about id. per mile per passenger. But the extra charges levied for the use of parlour, sleeping and other special cars, of which some of the best trains are exclusively composed, in practice constitute a differentiation of class, besides making the real cost of travelling higher than the figures just given.

In America and other countries where distances are great and passengers have to spend several days continuously in a train sleeping and restaurant cars are almost a necessity, and accordingly are to be found on most important through trains. Such cars in the United States are largely owned, not by the railway companies over whose lines they run, but by the Pullman Car Company, which receives the extra fees paid by passengers for their use. Similarly in Europe they are often the property of the International Sleeping Car Company (Compagnie Internationale des Wagons-Lits), and the supplementary fares required from those who travel in them add materially to the cost of a journey. In the United Kingdom, where the distances are comparatively small, sleeping and dining cars must be regarded rather as luxuries; still even so, they are to be met with very frequently. The first dining car in England was run experimentally by the Great Northern railway between London and Leeds in 1879, and now such vehicles form a common feature on express trains, being available for all classes of passengers without extra charge beyond the amount payable for food. The introduction of corridor carriages, enabling passengers to walk right through the trains, greatly increased their usefulness. The first English sleeping cars made their appearance in 1873, but they were very inferior to the vehicles now employed. In the most approved type at the present time a passage runs along one side of the car, and off it open a number of transverse compartments or berths resembling ships' cabins, mostly for one person only, and each having a lavatory of its own with cold, and sometimes hot, water laid on. A charge of 7s. 6d. or 10s., according to distance, is made for each bed, in addition to the first-class fare. In the United States the standard sleeping car has a central alley, and along the sides are two tiers of berths, arranged lengthwise with the car and screened off from the alley by curtains. To some extent cars divided into separate compartments are also in use in that country. On the continent of Europe the typical sleeping car has transverse compartments with two berths, one placed above the other.

The first railway carriages in England had four wheels with two axles, and this construction is still largely employed, especially for short-distance trains. Later, when increased length became desirable, six wheels with Passenger g g three axles came into use; vehicles of this kind were carria es. made about 30 ft. long, and contained four compartments for first-class passengers or five for second or third class, carrying in the latter case fifty persons. Their weight was in the neighbourhood of 10 tons. In both the four-wheeled and the six-wheeled types the axles were free to rise and fall on springs through a limited range, but not to turn with respect to the body of the carriage, though the middle axle of the six-wheeled coach was allowed a certain amount of lateral play. Thus the length of the body was limited, for to increase it involved an increase in the length of the rigid wheel base, which was incompatible with smooth and safe running on curves. (On the continent of Europe, however, six-wheeled vehicles are to be found much longer than those employed in Great Britain.) This difficulty is avoided by providing the vehicles with four axles (or six in the case of the largest and heaviest), mounted in pairs (or threes) at each end in a bogie or swivel truck, which being pivoted can move relatively to the body and adapt itself to the curvature of the line. This construction was introduced into England from America about 1874, and has since been extensively adopted, being now indeed standard for main line stock. It soon led to an increase in the length of the vehicles; thus in 1885 the Midland railway had four-wheeled bogie third-class carriages, with bodies 43 ft. long, holding seventy persons in seven compartments and weighing nearly 18 tons, and sixwheeled bogie composite carriages, 54 ft. long and weighing 23 tons, which included 3 first-class and .4 third-class compartments, with a cupboard for luggage, and held 58 passengers. The next advance, introduced on the Great Western railway in 1892, was the adoption of corridor carriages having a passage along one side, off which the compartments open, and connected to each other by vestibules, so that it is possible to pass from one end of the train to the other. This arrangement involves a further increase of length and weight. For instance, fourwheeled bogie third-class corridor carriages employed on the Midland railway at the beginning of the 10th century weighed nearly 25 tons, and had bodies measuring 50 ft.; yet they held only 36 passengers, because not only had the number of compartments been reduced to six, as compared with seven in the somewhat shorter carriage of 1885, by the introduction of a lavatory at each end, but each compartment held only 6 persons, instead of 10, owing to the narrowing of its width by the corridor.

It will be seen from these particulars - which are typical of what has happened not only on other British railways, but also on those of other countries - that much more space has to be provided and more weight hauled for each passenger than was formerly the case. Thus, on the Midland railway in 1885, each third-class passenger, supposing the carriage to have its full complement, was allowed o62 ft. of lineal length, and his proportion of the total weight was 5.7 cwt. Less than 20 years later the lineal length allowed each had increased to nearly 1.4 ft., and the weight to nearly 14 cwt. Passengers in sleeping cars appropriate still more space and weight; in Great Britain some of these cars, though 40 tons in weight and over 65 ft. in length, accommodate only 11 sleepers, each of whom thus occupies nearly 6 ft. of the length and requires over 31 tons of dead weight to be hauled.

In America the long open double-bogie passenger cars, as originally introduced by Ross Winans on the Baltimore & Ohio railway, are universally in use. They are distinguished essentially from the British type of carriage by having in the centre of the body a longitudinal passage, about 2 ft. wide, which runs their whole length, and each car having communication with those on either side of it, the conductor, and also vendors of books, papers and cigars, are enabled to pass right through the train. The cars are entered by steps at each end, and are provided with lavatories and a supply of iced water. The length is ordinarily about 50 ft., but sometimes 80 or go ft. The seats, holding two persons, are placed transversely on each side of the central passage, and have reversible backs, so that passengers can always sit facing the direction in which the train is travelling. Cars of this saloon type have been introduced into England for use on railways which have adopted electric traction, but owing to the narrower loading gauge of British railways it is not usually possible to seat four persons across the width of the car for its whole length, and at the ends the seats have to be placed along the sides of the vehicle. A considerable amount of standing room is then available, and those who have to occupy it have been nicknamed " straphangers," from the fact that they steady themselves against the motion of the train by the aid of leather straps fixed from the roof for that purpose. Cars built almost entirely of steel, in which the proportion of wood is reduced to a minimum, are used on some electric railways, in order to diminish danger from fire, and the same mode of construction is also being adopted for the rolling stock of steam railways.

End doors opening on end platforms have always been characteristic of American passenger equipment. Their use secures a continuous passage-way through the train, but is attended with some discomfort and risk when the train is in motion. The opening of the doors was apt to cause a disagreeable draught through the car in cold weather, and passengers occasionally fell from the open platform, or were blown from it, when the train was moving. To remedy these defects vestibules were introduced, to enclose the platform with a housing so arranged as to be continuous when the cars are made up into trains, and fitted with side doors for ingress and egress when the trains are standing. A second advantage of the vestibule developed in use, for it was found that the lateral swaying of the cars was diminished by the friction between the vestibule frames. The fundamental American vestibule patent, issued to H. H. Sessions of Chicago in November 1887, covered a housing in combination with a vertical metallic plate frame of the general contour of the central passage-way, which projected slightly beyond the line of the couplings and was held out by horizontal springs top and bottom, being connected with the platform housing by flexible connexions at the top and sides and by sliding plates below. A common form is illustrated in fig. 27. Subsequent improvements on the Sessions patent have resulted in a modified form of vestibule in which the housing is made the full width of the platform, though the contact plate and springs and the flexible connexions remain the same as before. The application of vestibules is practically limited to trains making long journeys, as it is an obstruction to the free ingress and egress of passengers on local trains that make frequent stops.

FIG. 27. - A " Vestibule "; the " lazytongs " gate is folded away when two cars are coupled together, giving free passage from end to end of the train.

In the United States the danger of the stoves that used to be employed for heating the interiors of the cars has been realized, and now the most common method is by steam taken from the locomotive boiler and circulated through the train in a line of piping, rendered continuous between the cars by flexible coupling-hose. The same method is finding increased favour in Great Britain, to the supersession of the old hot-water footwarmers. These in their simplest form are cans filled with water, which is heated by immersing them in a vessel containing boiling water. In some cases, however, they are filled with fused acetate of soda; this salt is solid when cold, but when the can containing it is heated by immersion in hot water it liquefies, and in the process absorbs heat which is given out again on the change of state back to solid. Such cans remain warm longer than those containing only hot water. On electric railways the trains are heated by electric heaters. As to lighting, the oil lamp has been largely displaced by gas and electricity. The former is often a rich oil-gas, stored in steel reservoirs under the coaches at a pressure of six or seven atmospheres, and passed through a reducing valve to the burners; these used to be of the ordinary fish-tail type, but inverted incandescent mantles are coming into increasing use. Gas has the disadvantage that in case of a collision its inflammability may assist ally fire that may be started. Electric light is free from this drawback. The current required for it is generated by dynamos driven from the axles of the coaches. With " set" or " block" trains, that is, trains having their vehicles permanently coupled up, one dynamo may serve for the whole train, but usually a dynamo is provided for each coach, which is then an /..,F?? o..? .................._ -..

independent unit complete in itself. It is necessary that the voltage of the current shall be constant whatever be the increase of the speed of the train, and therefore of the dynamo. In most of the systems that have been proposed this result is attained by electrical regulation; in one, however, a mechanical method is adopted, the dynamo being so' hung that it allows the driving belt to slip when the speed of the axle exceeds a certain limit, the armature thus being rotated at an approximately constant speed. In all the systems accumulators are required to maintain the light when the train is at rest or is moving too slowly to generate current.

In all countries passenger trains must vary in weight according to the different services they have to perform; suburban Weight trains, for example, meant to hold as many pas ah d sengers as possible, and travelling at low speeds, do not weigh so much as long-distance expresses, which include dining and sleeping cars, and on which, from considerations of comfort, more space must be allowed each occupant. The speed at which the journey has to be completed is obviously another important factor, though the increased power of modern locomotives permits trains to be heavier and at the same time to run as fast, and often faster, than was formerly possible, and in consequence the general tendency is towards increased weight as well as increased speed. An ordinary slow suburban train may weigh about loo tons exclusive of the engine, and may be timed at an inclusive speed, from the beginning to the end of its journey, as low as 12 or 15 m. an hour; while usually the fastest express trains maintaining inclusive speeds of say 45 m. an hour, and made up of the heaviest and strongest rolling stock, do not much exceed 300 tons in any country, and are often less. The inclusive speed over a long journey is of course a different thing from the average running speed, on account of the time consumed in intermediate stops; the fewer the stops the more easily is the inclusive speed increased, - hence the advantage of the non-stop runs of 150 and zoo m. or more which are now performed by several railways in Great Britain, and on which average speeds of 54 or 55 m. per hour are attained between stopping-places. Over shorter distances still more rapid running is occasionally arranged, and in Great Britain, France and the United States there are instances of trains scheduled to maintain an average speed of 60 m. an hour or more between stops. Still higher speeds, up to 75 or even 80 m. an hour, are reached, and sustained for shorter or longer distances every day by express trains whose average speed between any two stoppingplaces is very much less. But isolated examples of high speeds do not give the traveller much information as to the train service at his disposal, for on the whole he is better off with a large number of trains all maintaining a good average of speed than with a service mostly consisting of poor trains, but leavened with one or two exceptionally fast ones. If both the number and the speed of the trains be taken into account, Great Britain is generally admitted still to remain well ahead of any other country.

The vehicles used for the transportation of goods are known as goods wagons or trucks in Great Britain, and as freight cars in America. The principal types to be found in the United Kingdom and on the continent of Europe are open wagons (the lading often protected from the weather by tarpaulin sheets), mineral wagons, covered or box wagons for cotton, grain, &c., sheep and cattle trucks, &c. The principal types of American freight cars are box cars, gondola cars, coal cars, stock cars, tank cars and refrigerator cars, with, as in other countries, various special cars for special purposes. Most of these terms explain themselves. The gondola or flat car corresponds to the European open wagons and is used to carry goods not liable to be injured by the weather; but in the United States the practice of covering the load with tarpaulins is unknown, and therefore the proportion of box cars is much greater than in Europe. The long hauls in the United States make it specially important that the cars should carry a load in both directions, and so bcx cars which have carried grain or merchandise one way are filled with wool, coal, coke, ore, timber and other coarse articles for the return journey. On this account it is common to put small end doors, in American box cars, through which timber and rails may be loaded.

The fundamental difference between American freight cars. and the goods wagons of Europe and other lands is in carrying capacity. In Great Britain the mineral trucks can ordinarily hold from 8 to io tons (long tons, 2240 lb), and the goods trucks rather less, though there are wagons in use holding 12 or 15 tons, and the specifications agreed to by the railway companies associated in the Railway Clearing House permit private wagon owners (who own about 45% of the wagon stock run on the railways of the United Kingdom) to build also wagons holding 20, 30, 40 and 56 tons. On the continent of Europe the average carrying capacity is rather higher; though wagons of less than io tons capacity are in use, many of those originally rated at io tons have been rebuilt to hold 15, and the tendency is towards wagons of 15-20 tons as a standard, with others for special purposes holding 40 or 45 tons.

The majority of the wagons referred to above are comparatively short, are carried on four wheels, and are often made of wood. American cars, on the other hand, have long bodies mounted on two swivelling bogie-trucks of four wheels each, and are commonly constructed of steel. About 1875 their average capacity differed little from that of British wagons of the present day, but by 1885 it had grown to zo or 22 short tons (z000 ib) and now it is probably at least three times that of European wagons. For years the standard freight cars have held 60,000 lb and now many carry 80,000 lb or 100,000 lb; a few coal cars have even been built to contain 200,000 lb. This high carrying capacity has worked in several ways to reduce the cost of transportation. An ordinary British 10-ton wagon often weighs about 6 tons empty, and rarely much less than 5 tons; that is, the ratio of its possible paying load to its tare weight is at the best about 2 to 1. But an American car with a capacity of 10o,000 lb may weigh only 40,000 lb, and thus the ratio of its capacity to its tare weight is only about 5 to 2. Hence less dead weight has to behauled for each ton of paying load. In addition the increased size of the American freight car has diminished the interest on the first cost and the expenses of maintenance relatively to the work done; it has diminished to some extent the amount. of track and yard room required to perform a unit of work;, it has diminished journal and rolling friction relatively to thetons hauled, since these elements of train resistance grow relatively less as the load per wheel rises; and finally, it has tended to reduce the labour costs as the train loads have become greater, because no more men are required to handle a heavy train than; a light one.

It is sometimes argued that if these things are true for one country they must be true for another, and that in Great Britain, for example, the use of more capacious cars would bring down. the cost of carriage. It may be pointed out, however, that the social and geographical conditions are different in the United - Kingdom and the United States, and in each country the. methods of carrying goods and passengers have developed in accordance with the requirements of those conditions. In the one country the population is dense, large towns are numerous and close to one another, the greatest distances to be travelled are short, and relatively a large part of the freight to be carried is merchandise and manufactured material consigned in small quantities. In the other country precisely the opposite conditions exist. Under the first set of conditions quickness and flexibility of service are relatively more important than under the second set. Goods therefore are collected and: despatched promptly, and, to secure rapid transit, are packed'. in numerous wagons, each of which goes right through to its destination, with the consequence that, so far as general merchandise is concerned, the weight carried in each is a quarter - or less of its capacity. But if full loads cannot be arranged forsmall wagons, there is obviously no economy in introducing, larger ones. On the other hand, where, as in America, the great volume of freight is raw material and crude food-stuffs, and the distances are great, a low charge per unit of transportation is more important than any consideration such as quickness of delivery; therefore full car-loads of freight are massed into enormous trains, which run unbroken for distances of perhaps 1000 m. to a seaport or distributing centre.

The weight and speed of goods trains vary enormously according to local conditions, but the following figures, which refer to traffic on the London & North-Western railway between London and Rugby, may be taken as representative of good English practice. Coal trains, excluding the engine, weigh up to Boo or 900 tons, and travel at from 18 to 22 m. an hour; ordinary goods or merchandise trains, weighing 430 tons, travel at from 25 to 30 m. an hour; and quick merchandise trains with limited loads of 300 tons make 35 to 40 m. an hour. In the United States mineral and grain trains, running at perhaps 12 m. an hour, may weigh up to about 4000 tons, and loads of 2000 tons are common. Merchandise trains run faster and carry less. Their speed must obviously depend greatly on topographical conditions. In the great continental basin there are long lines with easy gradients and curves, while in the Allegheny and Rocky Mountains the gradients are stiff, and the curves numerous and of short radius. Such trains, therefore, range in weight from 600 to 1800 tons or even more, and the journey speeds from terminus to terminus, including stops, vary from 15 to 30 m. an hour, the rate of running rising in favourable circumstances to 40 or even 60 m. an hour.

The means by which vehicles are joined together into trains are of two kinds - automatic and non-automatic, the difference between them being that with the former the impact of two vehicles one on the other is sufficient to couple them without any human intervention such as is required with the latter. The common form of non-automatic coupler, used in Great Britain for goods wagons, consists of a chain and hook; the chain hangs loosely from a slot in the draw-bar, which terminates in a hook, and coupling is effected by slipping the =chain of one vehicle over the hook of the next. For this operation, or its reverse, a man has to go in between the wagons, unless, as in Great Britain, he is provided with a coupling-stick - that is, a pole having a peculiarly shaped hook at one end by which the chain can be caught and thrown on or off the drawbar hook. This coupling gear is placed centrally between a pair of buffers; formerly these were often left " dead " - that is, consisted of solid prolongations of the frame of the vehicle, but now they are made to work against springs which take up the shocks that occur when the wagons are thrown violently .against one another in shunting. In British practice the chains consist of three links, and are of such a length that when fully extended there is a space of a few inches between opposing buffers; this slack facilitates the starting of a heavy train, since the engine is able to start the wagons one by one and the weight of the train is not thrown on it all at once. For passenger trains and occasionally for fast goods trains screw couplings are substituted for the simple chains. In these the central bar which connects the two end links has screw threads cut upon it,;and by means of a lever can be turned so as either to shorten the coupling and bring the vehicles together till their buffers .are firmly pressed together, or to lengthen it to permit the end link to be lifted off the hook.

Another form of coupler, which used to be universal in the United States, though it has now been almost entirely superseded by the automatic coupler, was the " link and pin," which differed fundamentally from the couplers commonly used in Europe, in the fact that it was a buffer as well as a coupler, no :side buffers being fitted. In it the draw-bar, connected through a spring to the frame of the car, had at its outboard end a socket into which one end of a solid link was inserted and secured by a pin. The essential change from the link and pin to the automatic coupler is in the outboard end or head of the draw-bar. 'The socket that received the link is replaced by a hook, shown at A in fig. 28, which is usually called the knuckle. This hook swings on the pivot B, and has an arm which extends backwards, practically at right angles with the working face of the hook, FIG. 28. - Automatic Coupling for Freight Cars (U.S.A.).

in a cavity in the head, and engages with the locking-pin C. This locking-pin is lifted by a suitable lever which extends to one or both sides of the car; lifting it releases the knuckle, which is then free to swing open, disconnecting the two cars. The knuckle stands open until the coupling is pushed against another coupling, when the two hooks turn on their pivots to the position shown in fig. 28, and, the locking-pin dropping into place, the couplers are made fast. This arrangement is only partly automatic, since it often happens that when two cars are brought together to couple the knuckles are closed and must be opened by hand. There are various contrivances by which this may be done by a man standing clear of the cars, but often he must go in between their ends to reach the knuckle.

This form of automatic coupler has now gained practically universal acceptance in the United States. To effect this result required many years of discussion and experiment. The Master Car Builders' Association, a great body of mechanical officers organized especially to being about improvement and uniformity in details of construction and operation, expressed its sense of the importance of " self-coupling " so far back as 1874, but no device of the kind that could be considered useful had then been invented. At that time a member of the Association referred to the disappearance of automatic couplers which had been introduced thirty or forty years before. This body pursued the subject with more or less diligence, and in 1884 laid down the principle that the automatic coupler should be one acting in a vertical plane - that is, the engaging faces should be free to move up and down within a considerable range, in order to provide for the differences in the height of cars. By the fixing of this principle the task of the inventor was considerably simplified. In 1887 a committee reported that the coupler question was the " knottiest mechanical problem that had ever been presented to the railroad," and over 4000 attempted solutions were on record in the United States Patent Office. The committee had not found one that did not possess grave disadvantages, but concluded that the " principle of contact of the surfaces of vertical surfaces embodied in the Janney coupler afforded the best connexion for cars on curves and tangents "; and in 1887 the Association recommended the adoption of a coupler of the Janney type, which, as developed later, is shown in fig. 28. The method of constructing the working faces of this coupler is shown in fig. 29. The principle was patented, but the company owning the patent undertook to permit its free use by railway companies which were members of the Master Car Builders' Association, and thus threw open the underlying principle to competition. From that time the numerous patents have had reference merely to details. Many different couplers of the Janney type are patented and made by different firms, but the tendency is to equip new cars with one of only four or five standard makes. The adoption of automatic couplers was stimulated in some degree by laws enacted by the various states and by the United States; and the Safety Appliance Act passed by Congress in 1893 made it unlawful for railways to permit to be hauled on their lines after the ist of January 1898 any car used for interstate commerce that was not equipped with couplers which coupled automatically by impact, and which could be uncoupled without the necessity for men going in between the ends of the cars. The limit was extended to the 1 st of August 1900 by the Interstate Commerce Commission, which was given discretion in the matter.

Automatic couplers resembling the Janney are adopted in a few special cases in Great Britain and other European countries, FIG. 29. - Development of the Working Faces of the Janney Coupler. The sides of the square are 6 in., and the centres AA are taken at 2 in. from the top and bottom of the square. The circles A'A', which are struck with 2-inch radius, define the first portion of the knuckle. The inner circle B has a radius of 12 in. From its intersection with A'A' arcs are struck cutting B in two points. These intersections determine the centres of the semicircles CC which form the ends of the respective knuckles. These semicircles and the circles A'A' are joined by tangents and short arcs struck from the centre of the figure.

but the great majority of couplings remain non-automatic. It may be pointed out that the general employment of side buffers in Europe greatly complicates the problem of designing a satisfactory automatic coupling, while to do away with them and substitute the combined buffer-coupling, such as is used in the United States, would entail enormous difficulties in carrying on the traffic during the transition stage.

In the United States the Safety Appliance Act of 1893 also forbade the railways, after the 1st of January 1898, to run trains which did not contain a " sufficient number " of cars equipped with continuous brakes to enable the speed to be controlled from the engine. This law, however, did not serve in practice to secure so general a use of power brakes on freight trains as was thought desirable, and another act was passed in 1903 to give the Interstate Commerce Commission authority to prescribe what should be the minimum number of power-braked cars in each train. This minimum was at first fixed at 50%, but on and after the 1st of August 1906 it was raised to 75%, with the result that soon after that date practically all the rolling stock of American railways, whether passenger or freight, was provided with compressed air brakes. In the United Kingdom the Regulation of Railways Act 1889 empowered the Board of Trade to require all passenger trains, within a reasonable period, to be fitted with automatic continuous brakes, and now all the passenger stock, with a few trifling exceptions, is provided with either compressed-air or vacuum brakes (see Brake), and sometimes with both. But goods and mineral trains so fitted are rare, and the same is the case on the continent of Europe, where, however, such brakes are generally employed on passenger trains. (H. M. R.) Intra-Urban Railways The great concentration of population in cities during the 19th century brought into existence a class of railways to which the name of intra-urban may be applied. Such l i nes are primarily intended to supply quick means of passenger communication within the limits of cities, and are to be distinguished on the one hand from surface tramways, and on the other from those portions of trunk or other lines which lie within city boundaries, although the latter may incidentally do a local or intra-urban business. Intra-urban railways, as compared with ordinary railways, are characterized by shortness of length, great cost per mile, and by a traffic almost exclusively passenger, the burden of which is enormously heavy. For the purpose of connecting the greatest possible number of points of concentrated travel, the first railways were laid round the boundaries of areas approximately circular, the theory being that the short walk from the circumference of the circle to any point within it would be no serious detention. It has been found, however, in the case of such circular or belt railways, that the time lost in traversing the circle and in walking from the circumference to the centre is so great that the gain in journey speed over a direct surface tramway or omnibus is entirely lost. Later intra-urban railways in nearly every case have been built, so far as possible,. on straight lines, radiating from the business centre or point of maximum congestion of travel to the outer limits of the city; and, while not attempting to serve all the population through the agency of the line, make an effort to serve a portion in the best possible manner - that is, with direct transit.

The actual beginning of the construction of intra-urban railways was in 1853, when powers were obtained to build a line, 24 m. long, from Edgware Road to King's Cross, in London, from which beginning the Metropolitan and Metropolitan District railways developed. These railways, which in part are operated jointly, were given a circular location, but the shortcomings of this plan soon became apparent. It was found that there was not sufficient traffic to support them as purely intra-urban lines, and they have since been extended into the outskirts of London to reach the suburban traffic.

The Metropolitan and Metropolitan District railways followed the art of railway building as it existed at the time they were laid out. Wherever possible the lines were constructed in open cutting, to ensure adequate ventilation; and where this was not possible they were built by a method suggestively named " cut and cover." A trench was first excavated to the proper depth, then the side walls and arched roof of brick were put in place, earth was filled in behind and over the arch, and the surface of the ground restored, either by paving where streets were followed, or by actually being built over with houses where the lines passed under private property. Where the depth to rail-level was too great for cut-and-cover methods, ordinary tunnelling processes were used; and where the trench was too shallow for the arched roof, heavy girders, sometimes of cast iron, bridged it between the side walls, longitudinal. arches being turned between them (fig. 30).

-- ice _ 1 - /f r- - f? h - - 2 FIG. 30. - Type-Section of Arched Covered Way, Metropolitan District railway, London.

The next development in intra-urban railways was an elevated line in the city of New York. Probably the first suggestion for an elevated railway was made by Colonel Stevens, of Hoboken, New Jersey, as early as 1831, when the whole art of railway construction was in its infancy. He proposed to build an elevated railway on a single line of posts, placed along the curb-line of the street: a suggestion which embodies not only the general plan of an elevated structure, but the most striking feature of it as subsequently built - namely, a railway supported by a single row of columns. The first actual work, however, was not begun till 1870, when the construction of an iron structure on a single row of columns was undertaken. The superiority, so far as the convenience of passengers is concerned, of an elevated over an underground railway, when both are worked by steam locomotives, and the great economy and rapidity of construction, led to the quick development and extension of this general design. By the year 1878 there were four parallel lines in the city of New York, and constructions of the same character had already been projected in Brooklyn and Chicago and, with certain modifications of details, in Berlin. In the year 1894 an elevated railway was built in Liverpool, and in 1900 a similar railway was constructed in Boston, U.S.A., and the construction of a new one undertaken in New York. These elevated railways as a rule follow the lines of streets, and are of two general types. One (fig. 31), the earliest form, consisted of a single row of columns supporting two lines of longitudinal girders carrying the rails, the lateral stability of the structure being obtained by anchoring the feet of the columns to their foundations. The other type (fig. 32) has two rows of columns connected at the top by transverse girders, which in turn carry the longitudinal girders that support the railway. In Berlin, on the Stadtbahn - which for a part of its length traverses private property - masonry arches, or earthen embankments between retaining walls, were substituted for the metallic structure wherever possible.

The next great development, marking the third step in the progress of intra-urban railway construction, took place in 1886, when J. H. Greathead (q.v.) began the City & South London railway, extending under the Thames from the Monument to Stockwell, a distance of 32 m. Its promoters recognized the unsuitability of ordinary steam locomotives for underground railways, and intended to work it by means of a moving cable; but before it was completed, electric traction had developed so far as to be available for use on such lines. Electricity, therefore, and not the cable, was installed (fig. 33). In the details of construction the shield was the novelty. In principle it had been invented by Sir Marc I. Brunel for the construction of the original Thames tunnel, and it was afterwards improved by Beach, of New York, and finally developed by Greathead. (For the details of the shield and method of its operation, see Tunnel.) By means of the shield Greathead cut a circular hole at a depth ranging from 40 to 80 ft.

below the surface, with an external diameter of 10 ft. 9 in.; this he lined with cast-iron segments bolted together, giving a sr 2 / FIG. 33. - Section of Tunnel and Electric Locomotive, City & South London railway.

clear diameter of 10 ft. 2 in. Except at the shafts, which were sunk on proposed station sites, there was no interference with the surface of the streets or with street traffic during construction. Two tunnels were built approximately parallel, each taking a single track. The cross-section of the cars was made to conform approximately to the section of the tunnel, the idea being that each train would act like a piston in a cylinder, expelling in front of it a column of air, to be forced up the station shaft next ahead of the train, and sucking down a similar column through the station shaft just behind. This arrangement was expected to ensure a sufficient change in air to keep such railways properly ventilated, but experience has proved it to be ineffective for the purpose. This method of construction has been used for building other railways in Glasgow and London, and in the latter city alone the " tube railways " of this character have a length of some 40 m. The later examples of these railways have a diameter ranging from 13 to 15 ft.

The fourth step in the development of intra-urban railways was to go to the other extreme from the deep tunnel which Greathead introduced. In 1893 the construction was completed in Budapest of an underground railway with a thin, flat roof, consisting of steel beams set close together, with small longitudinal jack arches between them, the street pavement .

`,I FIG. 34. - Electric Underground Railway, Budapest.

resting directly on the roof thus formed (fig. 34). The object was to bring the level of the station platforms as close to the . FIG. 31. - Single-Column Elevated Structure Z9' 1'7 5-3 " FIG. 32. - Double-Column Elevated Structure (half-section).

surface of the street as the height of the car itself would permit; in the case of Budapest the distance is about q ft. This principle of construction has since been followed in the construction of the Boston subway, of the Chemin de Fer Metropolitain in Paris, and of the New York underground railway. The Paris line is built with the standard gauge of 4 ft 82 in., but its tunnels are designedly made of such a small crosssection that ordinary main line stock cannot pass through them.

The New York underground railway (fig. 35) marks a still further step in advance, in that there are practically two different railways in the same structure. One pair of tracks is used for a local service with stations about one-quarter of a mile apart, following the general plan of operation in vogue on all other intra-urban railways. The other, or central, pair of tracks is for trains making stops at longer distances. Thus there is a differentiation between the long-distance traveller who desires to be carried from one extreme of the city to the other and the short-distance traveller who is going between points at a much less distance.

To sum up, there are of intra-urban railways two distinct classes: the elevated and the underground. The elevated is used where the traffic is so light as not to warrant the expensive underground construction, or where the construction of an elevated line is of no serious detriment to the adjoining property. The underground is used where the congestion of traffic is so great as to demand a railway almost regardless of cost, and where the conditions of surface traffic or of adjoining property are such as to require that the railway shall not obstruct or occupy any ground above the surface.

Underground railways are of three general types: the one of extreme depth, built by tunnelling methods, usually with the shield and without regard to the surface topography, where the stations are put at such depth as to require lifts to carry the passengers from the station platform to the street level. This type has the advantage of economy in first construction, there being the minimum amount of material to be excavated, and no interference during construction with street traffic or subsurface structures; it has, however, the disadvantage of the cost of o p eration of lifts at the stations. The other extreme type is the shallow construction, where the railway is brought to the minimum distance below the street level. This system has the advantage of the greatest convenience in operation, no lifts being required, since the distance from the street surface to the station platform is about 12 to 15 ft.; it has the disadvantages, however, of necessitating the tearing up of the street surface during construction, and the readjustment of sewer, water, gas and electric mains and other subsurface structures, and of having the gradients partially dependent on the surface topography. The third type is the intermediate one between those two, followed by the Metropolitan and Metropolitan District railways, in London, where the railway has an arched roof, built usually at a sufficient distance below the surface of the street to permit the other subsurface structures to lie in the ground above the crown of the arch, and where the station platforms are from 20 to 30 ft. beneath the surface of the street - a depth not sufficient to warrant the introduction of lifts, but enough to be inconvenient.

In the operation of intra-urban railwa y s, steam locomotives, cables and electricity have severally been tried: the first having been used in the earlier examples of underground lines and in the various elevated systems in the United States. The fouling of the air that results from the steam-engine, owing to the production of carbonic acid gas and of sulphurous fumes and aqueous vapour, is well known, and its use is now practically abandoned for underground working. The cable is slow; and unless development along new lines of com p ressed air or some sort of chemical engine takes place, electricity will monopolize the field. Electricity is applied through a separate locomotive attached to the head of the train, or through motor carriages attached either at one end or at both ends of the train, or by putting a motor on every axle and so utilizing the whole weight of the train for traction, all the motors being under a single control at the head of the train, or at any point of the train for emergency. The distance between stations on intra-urban railways is governed by the density of local traffic and the speed desired to be maintained. As a general rule the interval varies from one-quarter to one-half mile; on the express lines of the New York underground railway, the inter-station interval averages about r1 m. On steam-worked lines the speed of trains is about i r to 15 m. per hour, according to the distance between stations Later practice takes advantage of the great increase in power that can be temporarily developed by electric motors during the period of acceleration; this, in proportion to the weight of the train to be hauled, gives results much in advance of those obtained on ordinary steam railways. Since high average speed on a line with frequent stops depends largely on rapidity of acceleration, the tendency in modern equipment is to secure as great an output of power as possible during the accelerating period, with corresponding increase in weight available for adhesion. With a steam locomotive all the power is concentrated in one machine, and therefore the weight on the drivers available for adhesion is limited. With electricity, power can be applied to as many axles in the train as desired, and so the whole weight of the train, with its load, may be utilized if necessary. Sometimes, as on the Central London railway, the acceleration of gravity is also utilized; the different stations stand, as it were, on the top of a hill, so that outgoing trains are aided at the start by having a slope to run down, while incoming ones are checked by the rising gradient they encounter.

The cost of intra-urban railways depends not only on the type of construction, but more especially upon local conditions, such as the nature of the soil, the presence of subsurface structures, like sewers, water and gas mains, electric conduits, &c.; the necessity of permanent underpinning or temporary supporting of house foundations, the cost of acquiring land passed under or over when street lines are not followed, and, in the case of elevated railways, the cost of acquiring easements of light, air and access, which the courts have held are vested in the abutting property. The cost of building an ordinary two-track elevated railway according to American practice varies from $300,000 to $400,000 a mile, exclusive of equipment, terminals or land damages. The cost of constructing the deep tubular tunnels in London, whose diameter is about 15 ft. exclusive, in like manner, of equipment, terminals or land damages, is about b70,000 to L200,000 a mile. The cost of the Metropolitan and Metropolitan District railways of London varied greatly on account of the variations in construction. The most difficult section - namely, that under Cannon Street - where the abutting buildings had to be underpinned, and a very dense traffic maintained during construction, while a network of sewers and mains was readjusted, cost at the rate of about r,000,000 a mile. The contract price of the New York underground railway, exclusive of the incidentals above mentioned, was $35,000,000 for 21 m., of which 16 m. are underground and 5 are elevated. The most difficult portion of the road, 41 m. of four-track line, cost $15,000,000. (W. B. P.) FIG. 35. - New York Rapid Transit railway, showing also the tracks and conduits of the electric surface tramway.

The term light railways is somewhat vague and indefinite, and therefore to give a precise definition of its significance is not an easy matter. No adequate definition is to be found even in the British statute-book; for although g parliament has on different occasions passed acts dealing with such railways both in Great Britain and Ireland, it has not inserted in any of them a clear and sufficient statement of what it intends shall be understood by the term, as distinguished from an ordinary railway. Since the passing of the Light Railways Act of 1896, which did not apply to Ireland, it is possible to give a formal definition by saying that a light railway is one constructed under the provisions of that act; but it must be noted that the commissioners appointed under that act have authorized many lines which in their physical characteristics are indistinguishable from street tramways constructed under the Tramways Act, and to these the term light railways would certainly not be applied in ordinary parlance. Still, they do differ from ordinary tramways in the important fact that the procedure by which they have been authorized is simpler and cheaper than the methods by which special private acts of parliament have to he obtained for tramway projects. Economy in capital outlay and cheapness in construction is indeed the characteristic generally associated with light railways by the public, and implicitly attached to them by parliament in the act of 1896, and any simplifications of the engineering or mechanical features they may exhibit compared with the standard railways of the country are mainly, if not entirely, due to the desire to keep down their expenses.

The saving of cost is effected in two ways: (I) Instead of having to incur the expenses of a protracted inquiry before parliament, the promoters of a light railway under the act of 1896 make an application to the light railway commissioners, who then hold a local inquiry, to obtain evidence of the usefulness of the proposed railway, and to hear objections to it, and, if they are satisfied, settle the draft order and hand it over to the Board of Trade for confirmation. The Board may reject the order if it thinks the scheme to be of such magnitude or importance that it ought to come under the direct consideration of parliament, or it may modify it in certain respects, or it may remit it to the commissioners for further inquiry. But once the order is confirmed by the Board, with or without modifications, it has effect as if it had been enacted by parliament, and it cannot afterwards be upset on the ground of any alleged irregularity in the proceedings. (2) The second source of economy is to be sought in the reduced cost of actually making the line and cf working it when made. Thus the gauge may be narrow, the line single, the rails lighter than those used in standard practice, while deep cuttings and high embankments may be avoided by permitting the curves to be sharper and the gradients steeper: such points conduce to cheapness of construction. Again, low speeds, light stock, less stringent requirements as to continuous brakes, signals, block-working and interlocking, road-crossings, stations, &c., tend to cheapness in working. On the lines actually authorized by the Board of Trade under the 1896 act the normal minimum radius of the curves has been fixed at about 600 ft.; when a still smaller radius has been necessary, the speed has been reduced to 10 m. an hour and a guard-rail insisted on inside the curve. Again, the speed has been restricted to 20 m. an hour on long inclines with gradients steeper than i in 50, and also on a line which had scarcely any straight portions and in which there were many curves of 600 ft. radius and gradients of 1 in 50. In the case of a line of 22 ft. gauge, with a ruling gradient of I in 40, a maximum speed of 15 m. an hour and a minimum radius of curve of 300 ft. have been prescribed. Curves of still smaller radius have entailed a maximum speed of io m. an hour. It must be understood that a railway described as " light " is not necessarily built of narrower gauge than the standard. Many lines, indeed, have been designed on the normal 4 ft. 82 in. gauge, and laid with rails weighing from 50 to 70 lb per yard; a flat-footed 60 lb rail, with the axle load limited to 14 tons, has the advantage for such lines that it permits the employment of a proportion of the locomotives used on main lines. The orders actually granted have allowed 50 lb, 56 lb, 60 lb and 70 lb rails, with corresponding axle loads of 10, 12, 14 and 16 tons. On a line of 2 ft. gauge, rails of 40 lb have been sanctioned. In regard to fencing and precautions at level-crossings, less rigid requirements may be enforced than with standard railways; and in some cases where trains are likely to be few, it has been provided that the normal position of the gates at crossings shall be across the line. Again, if the speed is low and the trains infrequent, the signalling arrangements may be of a very simple and inexpensive kind, or even dispensed with altogether. It should be mentioned that the act provided that the Treasury might advance a portion of the money required for a line in cases where the council of any county, borough or district had agreed to do the same, and might also make a special advance in aid of a light railway which was certified by the Board of Agriculture to be beneficial to agriculture in any cultivated district, or by the Board of Trade to furnish a means of communication between a fishing-harbour and a market in a district where it would not be constructed without special assistance from the s' ate.

As a general classification the commissioners have divided the schemes that have come before them into three classes: (A) those which like ordinary railways take their own line across country; (B) those in connexion with which it is proposed to use the public roads conjointly with the ordinary road traffic; and (Neutral) which includes inclined railways worked with a rope, and lines which possess the conditions of A and B in about equal porportions.

The Light Railways Act 1896 was to remain in force only until the end of 1901 unless continued by parliament, but it was continued year by year under the Expiring Laws Continuance Act. In 1901 the president of the Board of Trade it troduced a bill to continue the act until 1906, and to amend it so as to make it authorize the construction of a light railway on any highway, the object being to abolish the restriction that a light railway should run into the area of at least two local authorities; but it was not proceeded with. Towards the end of 1901 a departmental committee of the Board of Trade was formed to consider the Light Railways Act, and in 1902 the president of the Board of Trade (Mr Gerald Balfour) stated that as a result of the deliberations of this committee, a new bill had been drafted which he thought would go very far to meet all the reasonable objections that had been urged against the present powers of the local authorities. This bill, however, was not brought forward. In July 1903, Lord Wolverton, on behalf of the Board of Trade, introduced a bill to continue and amend the Light Railways Act. It provided that the powers of the light railway commissioners should continue until determined by parliament, and also provided, inter alia, that in cases where the Board of Trade thought, under section (9) subsection (3) of the original act, that a proposal should be submitted to parliament, the Board of Trade itself might submit the proposals to parliament by bringing in a bill for the confirmation of the light railway order, with a special report upon it. Opposition on petition could be heard before a select committee or a joint committee as in the case of private bills. The bill was withdrawn on the 11th of August 1903, Lord Morley appealing to the Board of Trade to bring in a more comprehensive measure to amend the unsatisfactory state of legislation in relation to tramways and light railways. In 1904 the president of the Board of Trade brought in a bill on practically the same lines as the amending bill of 1903. It reached second reading but was not proceeded with. Similar amending bills were introduced in the 1905 and 1906 sessions, but were withdrawn. During the first ten years after the act came into force 545 applications for orders were received, 313 orders were made, and 282 orders were confirmed. The orders confirmed were for 1731 m., involving an estimated capital expenditure of (12,770,384. At the end of 1906 only 500 m. had been opened for traffic, and the mileage of lines opened was much less in proportion to the mileage sanctioned in the cases of lines constructed on their own land than in the case of lines more of the nature of tramways. (In other countries where the mileage of main lines of railways in proportion to area and population is roughly the same as in the United Kingdom, the mileage of light railways already constructed is considerable, while many additional lines are under construction. At the end of 1903 there were 6150 m. working in France, costing on an average £4500 per mile, earning £275 per mile per annum; 3730 miles in Prussia costing £4180 per mile, earning £310 per mile per annum; 1430 m. in Belgium at £3400 per mile, earning £320 per mile per annum.) The average cost per mile in Great Britain on the basis of the prescribed estimates is £5860, but this figure does not include the cost of equipment and does not cover the whole cost of construction. According to the light railway commissioners, experience satisfied them (a) that light railways were much needed in many parts of the country and that many of the lines proposed, but not constructed, were in fact necessary to admit of the progress, and even the maintenance, of existing trade interests; and (b) that improved means of access were requisite to assist in retaining the population on the land, to counteract the remoteness of rural districts, and also, in the neighbourhood of industrial centres, to cope with the difficulties as to housing and the supply of labour. They pointed out that while during the first five years the act was in force there were 315 applications for orders, during the second five years there were only 142 applications, and that proposals for new lines had become less numerous owing to the various difficulties in carrying them to a successful completion and to the difficulty of raising the necessary capital even when part of it was provided with the aid of the state and of the local authorities. They expressed the opinion that an improvement could be effected enabling the construction of many much-needed lines by an amendment of some of the provisions of the Light Railways Act, and by a reconsideration of the conditions under which financial or other assistance should be granted to such lines by the state and by local authorities.

The so-called light railways in the United States and the British colonies have been made under the conditions peculiar to new countries. Their primary object being the development and peopling of the land, they have naturally been made as cheaply as possible; and as in such cases the cost of the land is inconsiderable, economy has been sought by the use of lighter and rougher permanent way, plant, rolling stock, &c. Such railways are not " light " in the technical sense of having been made under enactments intended to secure permanent lowness of cost as compared with standard lines. On the continent of Europe many countries have encouraged railways which are light in that sense. France began to move in this direction in 1865, and has formulated elaborate provisions for their construction and regulation. Italy did the same in its laws in 1873, 1879, 1881, 1887 and 1889; and Germany fostered enterprise of this kind by the imperial edicts, of 1875, 1878 and 1892. Holland, Hungary and Switzerland were all early in the field; and Belgium has succeeded, through the instrumentality of the semi-official Societe Nationale de Chemins de Fer Vicinaux, started in 1885, in developing one of the most complete systems of rural railway transport in the world.

In France the lines which best correspond to British light railways are called Chemins de fer d'interit local. These are regulated by France. a decree No. 11,264 of 6th August 1881, which the Ministry of Public Works is charged to carry out. The model " form of regulation " lays down the scales of the drawings and the information to be shown thereon. For the first installation a single line is prescribed, but the concessionaire must provide space and be prepared to double when required. The gauge may be either 1.44 metres (4 ft. 8.7 in.), or 1 metre (3 ft. 3.37 in.), or 75 metre (2 ft. 5.5 in.). The radius of curves for the 1 . 44 m. gauge must not be less than 250 metres, loo metres for the 1 m. gauge and 50 metres for the 75 m. gauge. A straight length of not less than 60 metres for the largest gauge and 40 metres for the smallest must be made between two curves having opposite directions. Except in special cases, gradients must not exceed 3 in moo; and between gradients in the opposite sense there must be not less than 60 metres of level for 1.44 m. and 40 metres for i m. and .75 m. gauges. The position of stations and stopping-places is regulated by the council of the department. The undertaking, once approved, is regarded as a work of public utility, and the undertakers are invested with all the rights that a public department would have in the case of the carrying out of public works. At the end of the period of the concession the department comes into possession of the road and all its fixed appurtenances, and in the last five years of the period the department has the right to enter into possession of the line, and apply the revenue to putting it into a thorough state of repair. It has also the right to purchase the undertaking at the end of the first fifteen years, the net profits of the preceding seven years to govern the calculation of the purchase price. The maximum 1st, 2nd and 3rd class passenger fares are, per kilometre, 067 f. (. 6d.), .050 f. (.455d.) and. 037 f. (34d.) respectively, when the trains are run at grande vitesse, the fares including 30 kilogrammes weight of personal baggage.

In Belgium a public company under government control (" Societe Nationale de Chemins de Fer Vicinaux ") does all that in France forms the responsibility of the Ministry of the Interior Belgium. and of the prefect of the department. Over an average of years it appears that 27% of the capital cost was found by the state, 28% by the province, 40.9% by the communes and 4 . I % by private individuals. At the end of 1908 there were 2085 m. in operation, and the total mileage authorized was 2603, while the construction of a considerable further mileage was under consideration. As far as possible, these railways are laid beside roads, in preference to independent formation; the permanent way costs £977 per mile in the former as against £793 in the latter. If laid in paving, the price varies between £1108 and £2266 per mile. Through villages, and where roads have to be crossed, the line is of the usual tramway type. The line is of m metre gauge, with steel rails weighing 212 kilos (42 lb) per yard. In the towns a deeper rail is used, weighing about 60 lb per yard. In three lines of the Vicinaux system, in the aggregate 45 m. in length, the sharpest curves are 30 metres, 35 metres and 40 metres respectively. There are gradients of I in 20 and I in 25. The speed is limited to 30 kilometres (about 18 m.) in the country and 6 m. per hour in towns and through villages.

In Italy many railways which otherwise fulfil the conditions of a light railway are constructed with a gauge of 4 ft. 82 in. The weights are governed by what the railway has to carry Italy. and the speed. Light locomotives, light rails and light rolling stock are employed. There are no bridges, except where watercourses occur. Cuttings are reduced to a minimum; and where the roads are sufficiently wide, the rails are laid on the margins. The advantage of uniformity of gauge is in the use of trucks for goods which belong to the rolling stock of the main lines. In Italy these railways are called " economic railways," and are divided into five types. Types I., II. and III. are of 4 ft. 82 in. gauge, type IV. of 0 . 95 m. and type V. of 070 m.; but as there is no example of type V., the classification is practically one of 1 '445 m. (4 ft. 82 in.) and one of 0.95 (3 ft. 0.5 in.). The chief difference between the first three types lies in the weight of rails and rolling stock and in the radius of the curves. The real light railway of Italy is that of type IV.: gauge, 0.95 m. (3 ft. 0.5 in.); weight of rails, 12 (26.45 lb) to 20 (44 lb) kilos; mean load per axle, 6 tons; minimum curve, 70 m. (229 ft. 2.6 in.) radius; width of formation, 3.50 m. (t m ft. 5.5 in.); top width of ballast, 2.10 m. (6 ft. 10.7 in.); depth of ballast under sleepers, omo m. (3 ft. 9.5 in.); maximum gradient, I in 50; length of sleepers, 1.70 m. (5 ft. 6.92 in.); width between parapets and width of tunnels, 1 m. over width of carriage; height of tunnels, 5 m. (16 ft. 4.85 in.); locomotives, maximum weight per axle 6 tons, rigid wheel base 1 . 80 m. (5 ft. 10.86 in.), diameter of driving-wheels 1 m. (3 ft. 3.37 in.).

In Germany the use of light railways (Klein-bahnen) has made great strides. The gauges in use vary considerably between 4 ft. 82 in., the standard national gauge, and 1 ft. 114 in., Germany. which appears to be the smallest in use. They are under the control of the Post and Telegraph department, the state issuing loans to encourage the undertakings; the authorities in the provinces and communes also give support in various ways, and under various conditions, to public bodies or private persons who desire to promote or embark in the industry. These conditions, as well as the degree of control over the construction and working of the lines, are left to the regulation of the provincial governments. Similarly, the same authorities decide for themselves the conditions under which the public roads may be used, and the precautions for public safety, all subject to the confirmation of the imperial government.

What are known as " portable railways " should be included in the same category as light railways. With a 24 in. gauge,.

lines of a portable kind can be made very handily and the cost is very much less than that of a permanently railways. constructed light railway. The simplicity is great; they can be quickly mounted and dismounted; the correct gauge can be perfectly maintained; the sections of rails and sleepers (which are of iron) are very portable, and skilled labour is not required to lay or to take them up; the making of a " turn-out " is easy, by taking out a 15 ft. section of the way and substituting a section with points and crossings. The safe load per wheel varies between 12 cwt. on a io in. 16 lb wheel and 40 cwt. on an 18 in. 56 lb wheel. The rolling stock is constructed either for farm produce or heavy minerals, the latter holding io to 27 cub. ft. For timber, 4 or 5 ft. bogies can be used. A useful wagon for agricultural transport on a 24 in. gauge line is 16 ft. long by 5 ft. wide; it weighs 72 cwt. and costs X30. A portable line of this kind will have 20 lb steel rails and 2112 steel sleepers-4 ft. 6 in. long - to a mile, laid 2 ft. 6 in. apart centre to centre. The total cost per mile of such a line, including all bolts, nuts, fish-plates and fastenings, ready for laying, ,delivered in the United Kingdom, is under Soo a mile.

See Evans Austin, The Light Railways Act 1896, which contains the rules of the Board of Trade; W. H. Cole, Light Railways at Home and Abroad; Lieut.-Col. Addison, Report to the Board of Trade (1894) on Light Railways in Belgium. (C. E. W.; E. GA.)

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