Cheng

Cheng, Tscheng or Tschiang (Ger. Scheng), an ancient Chinese wind instrument, a primitive organ, containing the principle of the free reed which found application in the accordion, concertina and harmonium. The cheng resembles a tea-pot filled with bamboo pipes of graduated lengths. It consists of a gourd or turned wooden receptacle acting as wind reservoir, in the side of which is inserted an insufflation tube curved like a swan’s neck or the spout of a tea-pot. The cup-shaped reservoir is closed by means of a plate of horn pierced with seventeen round holes arranged round the edge in an unfinished circle, into which fit the bamboo pipes. The pipes are cylindrical as far as they are visible above the plate, but the lower end inserted in the wind reservoir is cut to the shape of a beak, somewhat like the mouthpiece of the clarinet, to receive the reed. The construction of the free reed is very simple: it consists of a thin plate of metal—gold according to the Jesuit missionary Joseph Amiot,1 but brass in the specimens brought to Europe—of the thickness of ordinary paper. In this plate is cut a rectangular flap or tongue which remains fixed at one end, while at the other the tongue is filed so that, instead of closing the aperture, it passes freely through, vibrating as the air is forced through the pipe (see Free-Reed Vibrator). The metal plate is fastened with wax longitudinally across the diameter of the beak end of the pipe, a little layer of wax being applied also to the free end of the vibrating tongue for the purpose of tuning by adding weight and impetus. About half an inch above the horn plate a small round hole or stop is bored through the pipe, which speaks only when this hole is covered by the finger. A longitudinal aperture about an inch long cut in the upper end of the bamboo pipe serves to determine the length of the vibrating column of air proper to respond to the vibrations of the free reed. The length of the bamboo above this opening is purely ornamental, as are also four or five of the seventeen pipes which have no reeds and do not speak, being merely inserted for the purposes of symmetry in design. The notes of the cheng, like those of the concertina, speak either by inspiration or expiration of air, the former being the more usual method. Mahillon states that performers on the cheng in China are rare, as the method of playing by inspiration induces inflammation of the throat.2 Amiot, who gives a description of the instrument with illustrations showing the construction, states that in the great Chinese encyclopaedia Eulh-ya, articles Yu and Ho, the Yu of ancient China was the large cheng with nineteen free reeds (twenty-four pipes), and the Ho the small cheng with thirteen reeds or seventeen pipes described in this article. The compass of the latter is given by him as the middle octave with chromatic intervals, the thirteenth note giving the octave of the first. Mahillon gives the compass of a modern cheng as follows:

E.F.F. Chladni,3 who examined a cheng sent from China to Herr Müller, organist of the church of St Nicholas, Leipzig, at the beginning of the 19th century, gives an excellent description of the instrument, reproducing in illustration a plate from Giulio Ferrario’s work on costume.4 Müller’s cheng had the same compass as Mahillon’s. Chladni’s article was motived by the publication of an account of the exhibition of G.J. Grenié’s Orgue expressif, invented about 1810, in the Conservatoire of Paris.5 Grenié’s invention, perfected by Alexandre and Debain about 1840, produced the harmonium. Kratzenstein (see under Harmonium) of St Petersburg was the first to apply the free reed to the organ in the second half of the 18th century. Inventions of similar instruments, which after a short life were relegated to oblivion, followed at the beginning of the 19th century. An interesting reproduction of a Persian cheng dating from the 10th or 11th century is to be seen on a Persian vase described and illustrated together with a shawm in the Gazette archéologique (tome xi., 1886).