Stereotyping was the invention of William Ged, of Edinburgh, in 1731, and was introduced into the United States by David Bruce, of New York, in 1813. The stereotype is simply a moulded duplicate of the type face as set up, the duplicate being cast in the form of a single block of metal, by first taking an impression in plastic material from the faces of the type, after being set up, to form the mould, and then casting, in an easily fusible metal, an exact duplicate of this type face in this mould. This art prevents the wear on the movable type involved in printing, and also avoids the locking up into permanent forms of a large body of valuable type, since a form may be set up, stereotyped, and the type then distributed and set up into another form. Stereotyping, although used in book printing, was not thought practical for newspaper work until about 1861, because of the length of time required for the formation and drying of the mould and the casting of the plate; but about this time great expedition in the formation of the plate was attained by the employment of a steam bed to dry the mould, and a novel form of papier maché matrix, or mould, which could be conveniently disposed around the cylinders of type. The dampened and plastic papier maché sheets are beaten into the face of the type form by means of brushes, are then removed, dried, and used as moulds to cast the stereotype plate from. A stereotype plate can now be made in about seven minutes.
FIG. 125.—PAPER PULP BEATING ENGINE.
Paper Making is an important adjunct of the printing art, and its formation cheaply into long rolls of uniform strength is an essential condition of success in the rapid web-perfecting printing press. A Frenchman named Louis Robert about 1799 was the first to make a continuous web of paper, and in 1800 he received from the French Government a reward of 8,000 francs for his discovery. His invention was subsequently taken up and carried to a success by the great English paper makers, the Fourdrinier Brothers, whose name has been given to the machine. In the Fourdrinier process rags are ground to a pulp by a revolving beater ([Fig. 125]) working in a tank of water. The pulp, duly beaten, refined, screened, and diluted with water, is then piped into the “flow-box” of the Fourdrinier machine. The “flow-box,” shown on right of [Fig. 126], is a deep rectangular chamber extending across the full width of the machine, from which the pulp flows out in a thin stream onto an endless belt of 70-mesh wire cloth which runs over end rollers. To prevent the stream of pulp from flowing laterally over the edges of the belt, two endless rubber guides or bands, two inches square in cross section, travel with the belt over the first twenty feet of its length, and run over two pulleys above the wire cloth. The upper half of the wire cloth belt is supported by and runs over a series of closely juxtaposed rollers. As the pulp passes from the “flow-box” the particles of fibre float in it just as an innumerable multitude of particles of cotton fibre would float in a stream of water. To unite and interlace the fibres the wire cloth belt is given a lateral oscillating or shaking movement, which serves to interlock the fibres. Meanwhile the water strains through the wire cloth, leaving a thin layer of moist interlaced fibre spread in a white sheet over the surface of the belt. The separation of the water is further assisted by suction boxes which extend across close beneath the upper run of the belt and are connected to suction pumps.
FIG. 126.—FOURDRINIER PAPER MACHINE.
The wire cloth with its layer of moist pulp now passes below a roll which compresses the fibre, and then leaving the machine seen in [Fig. 126] it passes below a second and larger roll covered with felt, which presses out more of the water. The fibre next passes to the “first press,” where it is caught up on an endless belt and passed between two rollers where more water is pressed out of the sheet. Then it passes through a “second press,” and finally the sheet commences a long journey up and down over a series of steam-heated drying rolls, by which the sheet is dried.
Wood-Pulp.—When a purchaser of one of the New York dailies reads the morning’s voluminous edition, he little realizes that he holds in his hands the remains of a billet of wood as large as a good-sized club, yet such is the case. Originally made from the fibres of the papyrus plant, and later from rags beaten into a pulp, paper for the printing of books and newspapers is now made almost entirely of wood. In the formation of paper pulp from wood two processes are employed, one known as the soda process, and the other the sulphite process. In both cases the wood is cut into fine chips, and then digested in great drums with chemicals to extract the resinous matter and leave the pure fibrous cellulose, which resembles raw cotton in texture. This industry was developed by Watt and Burgess in 1853 (U. S. Pat. No. 11,343, July 18, 1854), who invented the soda process; by Voelter (U. S. Pat. No. 21,161, Aug. 10, 1858), who devised means for comminuting or shredding the wood; and by Tilghman (U. S. Pat. No. 70,485, Nov. 5, 1867), who invented the sulphite process.