The Mergenthaler `Linotypo' machine was in vented by Ottmar Mergenthaler, and the first ma chine was completed in 1SS4. This machine takes its name from the fact that it sets up a line of molds, and casts a line of type, or rather a solid metal bar with raised letters on one edge, which is known as a 'slug' and is the same as if a line of types were fused solid. These molls or mat rices :ire small pieces of sheet metal, each with a letter im pressed on its edge, as .bows in Fig. I. They are placed in maga zine tubes, as shown in the illustration, Fig. 2, all the a's in one tube, all the b's 11', in another. and so on, the tubes being arranged ver tically in a continuous line. The machine has a keyboard like a typewriter. and the depression of a key as D, connected by a rod.
C. with the escapement, B, causes a matrix to drop into an inclined channel, E, down which it falls to the inclined traveling belt, F, by which it is carried to the assembler. or stick, C, where it takes its place in line. The spaces, I, be tween words are simply duplex wedges, dropped into position from a box, II, in the same way as the matrices when the finger key, J, is pressed. When the compositor has set all that will go into a line, the duplex wedges are slid one upon another, thus 'spacing out' the line, and the line so formed is carried over in front of a slot on the wheel K, where automatically the line of type is cast with metal from the reservoir, shown in detail in the distributor, T. whence they find their way to the appropriate magazine tubes, each matrix be ing released at the proper point. A speed of 4000 ems an hour is the average rate of a good Lino type operator, while those unusually expert at tain as high a speed as 5000 to 6000 ems. The
advantages of this machine are, among others, Fig. 3, and its sides and base planed, after which the mold wheel, K. makes a quarter of a revolu tion and the slug is deposited on a galley. The matrices meanwhile are released and passed over head to the bar, E, where thin teeth engage on its horizontal ribs. This bar rises as shown by the dotted line, and the matrices are carried up to that it gives constantly a new type-face to print from, and also that there is no distributing to be done, the slugs being remelted after they have been used. The 'spacing out' device is another and a very decided advantage. The Linotype ma chine has become the most extensively used of any machine ever devised for the mechanical com position of types, and in its latest form performs successfully the most intricate kinds of compo sition, including tabular matter and the use of several classes of characters.
The Langton `Monotype' machine, like the Mergenthaler 'Linotype,' is primarily a type casting machine, but with the radical distinction that it casts separately each letter, point, and sign, including the spaces. The machine is con structed in two parts, viz. a keyboard and a type-casting machine. The function of the key board is to punch a series of holes in a moving strip or ribbon of paper, which is unwound from one spool to another, passing under a series of punches in its journey. These punches are ope rated by striking the keys on the keyboard. The result of the keyboard operation is, therefore, a roll of perforated ribbon. This ribbon, when fed to the casting machine, initiates and controls all the operations which produce the cast type set in column width ready to take printed proofs from. :See PRINTING.