FIG. 72—A LINOTYPE MATRIX
A picture of a linotype matrix is shown in Figure 72. It is a plate of brass formed with ears A at the four corners. The type mold is shown at B and of course the thickness of the matrix varies with the width of the type letter it is designed to cast. In the top of the matrix there is a V-shaped slot C formed with teeth which are designed to engage grooves in a V-shaped bar over the matrix magazine. The teeth on the matrices are variously cut away and serve as keys to the different channels of the magazine. There is a different combination of teeth for each letter of the alphabet and all matrices of the same letter have the same combination of teeth. The teeth on the distributing bar are also cut away according to various combinations. After the line has been cast the matrices are all raised by their ears and fed one by one upon the distributing bar. Each matrix moves along until it arrives over the channel it is designed to enter when it comes to a gap in the teeth of the bar that are supporting it and drops into the magazine. Although there are but seven teeth on each side of the V-shaped bar, there are more than enough combinations possible to provide a characteristic one for every key of the keyboard. A matrix always has at least one pair of teeth in engagement with the bar until it reaches the gap that lets it fall into its own special channel of the magazine. The number of matrices of each character varies with the normal frequency of use of that letter. For instance, the letter e is very commonly used, and there must be many more e matrices than z matrices, but in any case the number need not be very large because the process of casting a line and redistributing the type does not take very long and the matrices are soon back in the magazine ready to be used over again. The casting and distributing operations are entirely automatic and while they are in process the compositor is setting a new line.
The method of spacing which was a later development of the linotype is also very ingenious. The compositor does not have to bother with the width of spaces required to fill out a line. He merely touches the space key at the end of each word and and a space bar drops into place. Each space bar is formed of a pair of wedges and after the line has been assembled the space bars are automatically expanded to fill out the line completely by mechanism which holds down one wedge member (A, Figure 73) and slides up the other (B).
INDIVIDUAL TYPE CASTING AND COMPOSING
FIG. 73.—A LINOTYPE SPACE BAR
The difficulties of casting the linotype slug proved a serious handicap in the earlier days of the linotype. The product of the machine could not compare in quality with precast hand-set individual type, although it served very well for newspapers; but the machine is now so far perfected that it is widely used for magazine and book composition. However before this stage of perfection was reached the demand for a machine that could do a higher grade of work led to the invention of another machine known as the “monotype.” The monotype consists actually of two machines, one of which is operated by a compositor and the other operated entirely automatically by the product of the first machine. The compositor operates a keyboard and thereby cuts perforations in a long strip of paper. These perforations are arranged in characteristic groups one for each key. The perforated paper is then run through the second machine and in accordance with the various perforations the separate types are cast and assembled into justified lines. Air flowing through the perforations operates a pneumatic mechanism which brings the proper molds into position and casts the separate types. The method of justifying the lines is very interesting. As in the linotype the operator merely touches a space key at the end of each word, but at the end of the line the mechanism automatically estimates the spaces to be filled and divides this by the number of spaces so that a characteristic group of perforations is punched when the compositor shifts to the next line. In the casting machine the paper ribbon runs through backward and the space group of perforations is encountered before the line is cast. This automatically adjusts the mechanism to cast spaces of the requisite size to fill out the line exactly.