By the common method of which we have now briefly described, only a single letter is cast at a time, and the operation has been nearly the same for upwards of seventy years ; a scheme was, however, set on foot by a Mr. White, about seventeen years ago, to enable the founder to cast a great number of letters at one time—thirty or more ; but it was not carried into practice by any of the founders. About the same time a Monsieur Didot, assisted by Mr. Donkin the engineer, constructed a machine for a similar purpose, which was also intended to perform all the operations of the work by the assistance of a boy only.
'I'he invention which we have now to describe is an improvement by Monsieur Didot upon his former highly ingenious machine, now rendered capable of casting 200 types at once, and to repeat the operation two or three times in a minute. A patent for this country was taken out by Mr. John Louis Pouchee, who a few years ago established a type-foundry in Little Queen-street, Holborn, where the machinery is at present in hill and successful operation. The great number of drawings which accompany the specification of this patent obliges us to select such portions only as will best give a just idea of its nature and construc tion ; and we have for the same reason thrown the side views into perspective, which exhibits the machine entire, as at Fig. 1. Fig. 3 represents one side of the mould separated into its component parts. Fig. 2 is a section of the several bars composing both sides of the mould. Fig. 4 exhibits a plan of the same, fitted into and encompassed by a frame of iron, a horizontal and perspective view of which is given at Fig. 1. The same letters refer to the same parts in each of the figures. a (Fig. 3) is a steel bar, with horizontal grooves, in which are formed the bodies of the types; b b is the bar which holds the matrices c e, each of which is arranged opposite to its respective groove in the bar a, to which it is screwed fast ; the bar d is then screwed down to the bar b, which holds the matrices c c firmly in their places. The bar a is next laid upon the bar a, which covers the grooves, and forms the upper sides of the square recesses, shown also at a e, Fig. 4. f is the break-bar, and is placed in front of the bar a ; a series of small nicks or openings are made in this bar, through which the fluid metal passes into the grooves and matrices, where the body and letters of the type are cast; the grooves are closed by the spaces between the nicks of the break-bur coming against them, and forming the feet of the types. The bar
g is laid upon the break-bar as a cover to it, and the whole six bars thus com bined form one side, or one half, of a pair of moulds, shown in section, Fig. 3. This section likewise exhibits the form of the apertures through which the fluid metal has to pass into the grooves and matrices ; h is a receptacle between the moulds for the fluid metal, previous to its being forced into them, as we shall presently describe. In preparing the moulds for casting, the several bars composing them are connected together as before mentioned, and laid upon a solid metallic bed upon the table k k, as shown at Fig. 4 : the sides of the iron frame / /, which turn upon joints, are then brought to bear sideways against the moulds ; the top piece m, which also turns upon a joint, is brought down over the mould bars, which it firmly secures by bringing the looped part of the swinging lever a, shown at Fig. 1, over the end of the top piece vs, which is effected by the aid of the hand lever p forcing the tongue o against the lower end of the swinging lever, when the latch z falls and makes all fast. Thus prepared, a sufficient quantity of the fluid metal is poured out of a ladle into the receptacle between the moulds ; a trigger at r is then pulled, when a string connected to it draws back a bolt or catch s, which supports the long lever t, and allows it to fall with the rammer q into the receptacle, which " drives with considerable force the fluid metal from thence into the moulds and matrices." On each side of the rammer q is fixed "a guard or housing, to prevent the liquid metal from being splashed over the operator." In order to withdraw the types from the moulds, the workman places his foot upon the step a, when the compound lever v acts upon the pin w, under the leg z, and forces out the rammer from between the moulds, which is then lifted up by the workman, until it has passed the catch s, which supports it in the position shown in the figure. The mould is now opened by throwing up the hasp ; the swinging lever a then releases the end of the top piece, and allows the frame to be opened, and the moulds to be removed to a table, where the bars which compose it are placed under cramps, and separated by means of wrenches: the types are then removed, and undergo the operations of dressing, &c. as mentioned in the earlipart of our subject.