The tremendous spread of literacy in the nineteenth century led to an increased demand for the printed word and faster printing. Of the various attempts at rapid typesetting made through the century, the most durable and successful was the Mergenthaler Linotype machine, which cast solid lines of type from assembled lines of brass matrixes. The operator strikes keys (A) just as a typist does: the keys activate clickers (B) that cause the matrixes to fall onto a belt (C) that guides them into the assembling stick (D), where the operator spaces his line exactly, using spring wedges called "space bands." As each line is completed, the operator touches a lever (E) which moves the stick upwards into a channel along which the assembled matrixes are moved into the casting vice (F). The vice moves downwards. At its lowest point it is tightly pressed against one of the moulds on the cogged casting wheel (G), when a spurt of molten metal from the machine's pot (H) is forced through to make the hot "slug" or line of type. Two processes follow. The wheel continues around and locks in another position to allow an arm to eject the slug onto the long galley (I) you can see in front of the machine. While this is happening, the vise rises to its highest point (J) where another arm pushes the matrixes onto the grooved teeth of the second elevator bar (K), which is at the end of a long arm (L); the long arm rises to the top of the machine, where another arm pushes them into the distributor (M). A spiral shaft constantly turning moves the matrixes along the distributor, with the teeth of the matrixes, shown in the next slide, locked into the grooves of the distributor bar. As each matrix reaches the point at which it should drop into its proper place in the magazine (N), the combination of teeth and grooves operates as a key, causing each matrix to drop back into its proper row in the magazine, where it is ready to be used again. No quantity of metal type was ever tied up with the Linotype; the operators could set one line very quickly while another was moving into the vice, another was casting, and a fourth was being distributed, which enabled them even as early as the 1890s to set thousands of words in an hour ready for printing, a rate faster than any compositor could ever reach. Furthermore, an error could be corrected simply by resetting the line in which the error occurred. The matrixes and the type metal, with normal care, could be used indefinitely. The Linotype is still common in Canadian printing houses, though filmsetting is increasingly used.
