TYPE-POUNDING. In the article PRINT ING a general view is given of the various steps in the invention of typography, or the art of printing from moveable types, and a brief notice of the individuals whose ingenuity Contributed, more or less, to the perfection of the process of type-founding. Most of the early printers, in England as well as on the Continent, were accustomed to cut and east their own types. It has since become a separate business The first and most important operation of a type-foundry is the formation of the punches, which are well-tempered pieces of steel, each of which bears on its surface a single letter, formed with the greatest possible accuracy by filing, cutting, and punching the hollows with smaller punches. The face of the punch exactly resembles that of the finished type, the letter being reversed, and in high relief. The punch-cutter has to exercise great care and judgment for mailing the letter of pre cisely the right size, form, and thickness, so that it may range well with other letters of the same Fount, or set. When the punch is com pleted and hardened, it is struck into a piece of copper, which, when it has received the impression from the end of the punch, is called a Matrix, and forms a mould for the face of the type.
The Mould for casting the type consists of two halves, each of which is made of steel, and attached, for convenience of holding, to a piece of wood. The two halves of the mould are so formed that they may be instantane ously fitted together, leaving a square funnel shaped opening at the top, by which the type metal is poured into the mould to form the body of the type, with the matrix at the bottom to form the letter or face. The two halves of the mould are capable of adjust ment to the varying widths of the letters. The type-metal is usually melted in a small cast-iron pot, set in brickwork with an en closed fire under it, and is poured into the mould by a very small ladle. The caster then jerks the mould quickly upwards by a peculiar motion of his arm, and thereby expels the air, and forces the fluid metal to enter the cavities of the matrix. Some foun
ders use a small force-pump to aid this When the metal is set, the caster removes the pressure of a long curved spring which is attached to the bottom of the mould, and thereby separates the matrix from the face of the type. The mould is thee opened, and the type is removed by the application of a hook attached to the upper part of the mould.
When the types leave the caster, each of them has a small block of metal attached to the shank, or body of the type, being that which filled the throat or funnel of the mould. These are removed by a boy. The next operation is that of rubbing the flat sides of the types upon a piece of gritstone. The types are then set up by boys in rows or lines, and these are firmly secured in long frames, which hold them together while the dresser scrapes or polishes the flat surface which form the top and bottom of the body, and cuts a groove or channel along their lower ends by means of a small iron plane. While they are in the frame the are also bearded, an operation which consists in planing away to a bevel the upper angle of the body at the feet of the letters. After dressing, the types are tied up in such lines as may be convenient, and the proportionate numbers of every type of which a fount con sists are selected. All the types belonging to one fount are distinguished by one or more grooves or nicks across the lower edge or bottom face of the body, by which simple contrivance the compositor is enabled to pick up the types and place them all upright without looking at the letter. These nicks are formed by the insertion of one or more wires in the mould. Four casters and two boys can cast, break, and rub 2,000 types in an hour.
The composition of type-metal greatly varies ; the chief component however is lead, alloyed by one or more of the following metals —iron, antimony, copper, brass, tin, and bis muth.