Page:The American Cyclopædia (1879) Volume XVI.djvu/105

 TYPE 93 degree of tenacity. Copper is sparingly used ; one per cent, of it gives to type metal a per- ceptible reddish tint. Type metal, although melting at a comparatively low heat, fills the mould with great solidity, and shrinks very slightly in cooling. It does not oxidize serious- ly when exposed to the action of air, water, ley, or ink. The durability of types has been greatly improved by the process of copper- facing, invented and patented in 1850 by Dr. L. V. Newton of New York. Through the agency of the electrotype battery (see GALVAN- ISM, vol. vii., p. 601) a thin film of copper is deposited on the face of the type, making an efficient protection against abrasion and rapid wear. The success of typography depends on the accuracy of the types. They must be made so that they can be combined and recombined and interchanged with the greatest facility. The page of a daily newspaper, which may contain 150,000 pieces of metal, must be truly square, as if made of one piece. The first step is the making of punches, which consists in cutting on the end of a short bar of soft steel a model for each character which will be used in the font or assortment of types. When the steel has been hardened, the punch is struck on the side of a thin bar of rolled copper, pro- ducing a reversed duplicate of the model type, which when truly squared and fitted to a mould constitutes the matrix. All the matrices of a font are made to fit one mould. The type mould consists of two firmly screwed combina- tions of several pieces of steel, making right and left halves, each of which is almost the counterpart of the other. These halves are immovable in the direction which determines the height or depth of the body, but are readi- ly adjustable in the direction which determines the width of the letters, so that they can pro- duce either 1 or W with no further delay than that caused by the change of matrix. At one end of the mould the matrix is fitted ; at the other end is an opening through which the melted metal is injected. The founding of book and newspaper types is now done by a type-casting machine, which contains in the ' centre of the framework a pot of type metal i kept fluid by a fire beneath. The mould is j connected with the melted metal through a channel. In the pot is fitted a piston or plung- er, which, receiving motion from a cam, forces the fluid metal through the channel into the mould and matrix. The metal injected, fused at low heat, and cooled by a blast of cold air, solidifies almost instantaneously. As soon as the mould receives the metal, it opens, the matrix springs backward, and a little hook throws out the type. The mould closes, the matrix falls into its seat, and the plunger in- jects a new supply of metal, which is again thrown out as a type. The speed of the ma- chine is governed by the time required for cooling the metal in the mould, varying from 70 types of pica to 150 types of nonpareil in a minute. The type thrown out of the mould is usually perfect as to face, but imperfect as to body. A long piece of metal, called the jet, is attached to the foot, and must be broken off ; the fracture made by this breaking must be grooved out ; the corners of the body are sharp or wiry, and must be rubbed down on a grind- stone. The types are then set up in rows and carefully examined, one by one, under a mag- nifying glass. The defective letters are thrown into the melting pot, and those approved are packed in paper, ready for the printer. For the large displayed letters of posters, types are made of wood, usually maple or bay mahogany, and rarely of smaller size than one square inch. As these types are used only in single lines, and are kept in true line by straight strips of wood called reglet, they do not require the accuracy of body which is indispensable in metal types. Wood types are made by an in- genious application of the pantagraph, the in- vention of William Leavenworth of Allentown, N. J., who introduced it in 1834. A tracing point at one end of the pantagraph follows the outline of a large model letter; this tracing motion is accurately repeated at the opposite end by a rapidly revolving cutter or router, which cuts a letter of similar shape out of a block of wood. The routing tool does nearly all the work ; only a few cuts of the graver are required to finish the type. The types of all American type founderies are made to the standard height of $ of an inch. British types are usually of the same height, but those of founderies on the European continent are variable; some German types are nearly an inch, and Russian types are more than an inch in height. In all countries the graduations of sizes or of bodies of types has been very irreg- ular. Pierre Simon Fournier of Paris, in 1V64, proposed the first practicable system. He di- vided a selected body of type, then known as " Cicero," into 12 equal parts, and made one such part, which he called a typographic point, the unitary basis for determining the dimen- sions of every larger size. All sizes were to be even multiples of the typographic point. Four- nier's system, which was adopted in France, had the serious defect of an undetermined size for the body Cicero. To remedy this defect, Didot fixed the body Cicero at fa part of the royal French foot, and gave all the bodies made therefrom standard numerical names, which defined the number of points belonging to each body. Didot's system is now used in nearly all type founderies on the continent, but it has the disadvantage of being based on a dis- used measure, the royal foot, and of being in entire disagreement with the French metrical system. It has not been adopted by any Eng- lish or American type founder. In 1822 George Bruce of New York introduced in his own type foundery a new system, in which the di- mensions of the bodies were determined by the rule of geometrical progression, doubling every seventh size in any part of the series of sizes, and making each size 12-2462 per cent.