1816.—ROBERT CLAYTON. A new method of preparing metal . . . types. The specification mainly relates to plate-printing, but concludes: “Thirdly, I obtain what I shall term alto or high-relief, by producing metal castings from wooden moulds or matrices, punched in wood with a cross-grain, which has been previously slightly charred or baked.”[199] The metal is bismuth, tin and lead in equal parts, or tin (4), bismuth (4), lead (3), and antimony (1). 1822.—WILLIAM CHURCH. Machine for casting the types and arranging them ready to be transferred to the composing machinery. A matrix-bar containing a series of matrices is applied to a mould-bar, with a corresponding number of moulds. At the time of casting the latter is applied to jets leading from the metal chest, which is supplied from a metal fountain connected with the metal pot, and furnished with a valve to prevent the return of the metal. After the casting, the mould-bar, drawn endways, cuts off communication with the metal, and brings the said types beneath a series of punches, which descend and force them out at the same time that the matrix-box is unlocked, and descends clear of the types . . . The mould-bar is kept cool during the process by a stream of water passing through it . . . The metal is injected by the descent of a plunger into the metal chest. The type, as cast, is carried direct into a composing machine, where it is set up by means of a mechanism worked by keys, resembling the notes of a piano.[200] 1823.—LOUIS JOHN POUCHÉE[201] (communicated by Didot of Paris). Machine calculated to cast from 150 to 200 types at each operation, the operation being repeated twice or oftener in a minute. The moulds are composed of steel bars. The first has horizontal grooves at right angles to its length, and forms the body of the letter. The second is a matrix-bar, screwed to the bottom of the first. The third bar forms the fourth side of the type-body. The feet of the type are made by the fourth, a “break bar,” with orifices communicating with each type-mould. Two of these moulds are placed side by side so as to form a trough between them, in which the molten metal is poured, nearly as high as the orifices on the “break bar.” On pulling a trigger by a string, a plunger at the end of a lever falls into the trough, and injects the metal into the moulds. The lever is slightly raised after the casting, by a treadle, after which the workman raises it by hand until it passes a catch, which retains it until the string is pulled again. The mould is then unclamped, the mould-bars drawn asunder by wrenches, the types are found adhering to the break bar like the teeth of a comb, when they are broken off and dressed in the usual way.