Clyde (Welsh, Clwyd, “far heard,” “strong,” the Glotta of Tacitus), the principal river of Lanarkshire, Scotland. It is also the name of the estuary which forms the largest and finest firth on the west coast.
1. The River.—Daer Water, rising in Gana Hill (2190 ft.) on the borders of Lanarkshire and Dumfriesshire, after a course of 10½ m., and Potrail Water, rising 3 m. farther W. in the same hilly country (1928 ft.), after running N.N.E. for 7 m., unite 3½ m. S. of Elvanfoot to form the Clyde, of which they are the principal headstreams, though many mountain burns in these upland regions are also contributory. The old rhyme that “Annan, Tweed and Clyde rise a’ out o’ ae hillside” is not true, for Little Clyde Burn here referred to, rising in Clyde Law (2190 ft.), is only an affluent and not a parent stream. From the junction of the Daer and Potrail the river pursues a direction mainly northwards for several miles, winding eastwards around Tinto Hill, somewhat north-westerly to near Carstairs, where it follows a serpentine course westwards and then southwards. From Harperfield, a point about 4 m. above Lanark, it assumes a north-westerly direction, which, roughly, it maintains for the rest of its course as a river, which is generally held to end at Dumbarton, where it merges in the Firth. Its principal tributaries on the right are the Medwin (16 m. long), entering near Carnwath, the Mouse (15 m.), joining it at Lanark, the South Calder (16 m.) above Bothwell, the North Calder (12 m.) below Uddingston, the Kelvin (21 m.) at Glasgow, and the Leven (7 m.) at Dumbarton. The chief left-hand affluents are the Elvan (8 m.), entering at Elvanfoot, the Duneaton (19 m.), joining a few miles above Roberton, the Garf (6½ m.) below Lamington, the Douglas (20 m.) above Bonnington, the Nethan (12 m.) at Crossford, the Avon (28 m.) at Hamilton, the Rotten Calder (10 m.) near Newton, and the Cart (1 m.), formed by the junction of the Black Cart (9 m.) and the White Cart (19 m.), below Renfrew.
The total length of the Clyde from the head of the Daer to Dumbarton is 106 m., and it drains an area estimated at 1481 sq. m. It is thus the third longest river in Scotland (being exceeded by the Spey and Tay), but in respect of the industries on its lower banks, and its sea-borne commerce, it is one of the most important rivers in the world. Near Lanark it is broken by the celebrated Falls, four in number, which are all found within a distance of 3¾ m. Bonnington Linn, the most graceful, 2 m. above Lanark, is divided into two parts by a mass of tree-clad rocks in mid-stream, and has a height of 30 ft. From this spot the river runs for half a mile through a rugged, red sandstone gorge till it reaches Corra Linn, the grandest of the Falls, where in three leaps, giving it the aspect of a splendid cascade, it makes a descent of 84 ft., which, however, it accomplishes during flood at a single bound. Almost ¾ m. below Corra Linn, Dundaff Linn is reached, a fall of only 10 ft. Farther down, 1¾ m. below Lanark, at Stonebyres Linn, reproducing the characteristic features of Corra Linn, the river descends in ordinary water in three leaps, and in flood in one bold drop of 80 ft. Within this space of 3¾ m. the river effects a total fall of 230 ft., or 611⁄3 ft. in the mile. From Stonebyres Linn to the sea the fall is practically 4 ft. in every mile. The chief villages and towns on or close to the river between its source and Glasgow are Crawford, Lamington, New Lanark, Lanark, Hamilton, Bothwell, Blantyre and Uddingston. At Bowling (pop. 1018)—the point of transhipment for the Forth and Clyde Canal—the river widens decidedly, the fairway being indicated by a stone wall continued seawards as far as Dumbarton. Dunglass Point, near Bowling, is the western terminus of the wall of Antoninus, or Grim’s Dyke; and in the grounds of Dunglass Castle, now a picturesque fragment, stands an obelisk to Henry Bell (1767-1830), the pioneer of steam navigation in Europe.
As far down as the falls the Clyde remains a pure fishing stream, but from the point at which it begins to receive the varied tribute of industry, its water grows more and more contaminated, and at Glasgow the work of pollution is completed. Towards the end of the 18th century the river was yet fordable at the Broomielaw in the heart of Glasgow, but since that period, by unexampled enterprise and unstinted expenditure of money, the stream has been converted into a waterway deep enough to allow liners and battleships to anchor in the harbour (see Glasgow).
Clydesdale, as the valley of the upper Clyde is called, begins in the district watered by headstreams of the river, the course of which in effect it follows as far as Bothwell, a distance of 50 m. It is renowned for its breed of cart-horses (specifically known as Clydesdales), its orchards, fruit fields and market gardens, its coal and iron mines.
2. The Firth.—From Dumbarton, where the firth is commonly considered to begin, to Ailsa Craig, where it ends, the fairway measures 64 m. Its width varies from 1 m. at Dumbarton to 37 m. from Girvan to the Mull of Kintyre. The depth varies from a low-tide minimum of 22 ft. in the navigable channel at Dumbarton to nearly 100 fathoms in the Sound of Bute and at other points. The Cumbraes, Bute and Arran are the principal islands in its waters. The sea lochs all lie on the Highland shore, and comprise Gare Loch, Loch Long, Loch Goil, Holy Loch, Loch Striven, Loch Riddon and Loch Fyne. The only rivers of any importance feeding the Firth are the Ayrshire streams, of which the chief are the Garnock, Irvine, Ayr, Doon and Girvan. The tide ascends above Glasgow, where its farther rise is barred by a weir. The head-ports are Glasgow, Port Glasgow, Greenock, Ardrossan, Irvine, Troon, Ayr and Campbeltown. In addition to harbour lights, beacons on rocks, and light-ships, there are lighthouses on Ailsa Craig, Sanda, Davaar, Pladda, Holy Isle, and Little Cumbrae, and at Turnberry Point, Cloch Point and Toward Point. The health and holiday resorts on the lochs, islands and mainland coast are numerous.