As soon as a word is complete, he touches the “spacing” lever at the side of the keyboard. The action causes a “space” to be placed against the last die to separate it from the following word. The operations are repeated until the tinkle of a bell warns him that, though there may be room for one or two more letters, the line will not admit another whole syllable. The line must therefore be “justified,” that is, the spaces between the words increased till the vacant room is filled in. In hand composition this takes a considerable time, and is irksome; but at the linotype the operator merely twists a handle and the wedge-shaped “spaces,” placed thin end upwards, are driven up simultaneously, giving the lateral expansion required to make the line of the right measure.
A word about the “spaces,” or space-bands. Were each a single wedge the pressure would be on the bottom only of the dies, and their tops, being able to move slightly, would admit lead between them. To obviate this a small second wedge, thin end downwards, is arranged to slide on the larger wedge, so that in all positions parallelism is secured. This smaller wedge is of the same shape as the dies and remains stationary in line with them, the larger one only moving.
The line of dies being now complete, it is automatically borne off and pressed into contact with the casting wheel. This wheel, revolving on its centre, has a slit in it corresponding in length and width to the size of line required. At first the slit is horizontal, and the dies fit against it so that the row of sunk letters on the faces are in the exact position to receive the molten lead, which is squirted through the slit from behind by an automatic pump, supplied from a metal-pot. The pot is kept at a proper heat of 550° Fahrenheit by the flames of a Bunsen burner.
The lead solidifies in an instant, and the “slug” of type is ready for removal, after its back has been carefully trimmed by a knife. The wheel revolves for a quarter-turn, bringing the slit into a vertical position; a punch drives out the “slug,” which is slid into the galley to join its predecessors. The wheel then resumes its former horizontal position in readiness for another cast.
The assembled dies have for the time done their work and must be returned to the magazine. The mechanism used to effect this is peculiarly ingenious.
An arm carrying a ribbed bar descends. The dies are pushed up, leaving the “spaces” behind to be restored to their proper compartment, till on a level with the ribbed bar, on to which they are slid by a lateral movement, the notches of the V-shaped opening in the top side of each die engaging with the ribs on the bar. The bar then ascends till it is in line with a longer bar of like section passing over the open top of the entire magazine. A set of horizontal screw-bars, rotating at high speed, transfer the dies from the short to the long bar, along which they move till, as a die comes above its proper division of the magazine, the arrangement of the teeth allows it to drop. While all this has been going on, the operator has composed another line of moulds, which will in turn be transferred to the casting wheel, and then back to the magazine. So that the three operations of composing, casting, and sorting moulds are in progress simultaneously in different parts of the machine; with the result that as many as 20,000 letters can be formed by an expert in the space of an hour, against the 1500 letters of a skilled hand compositor.
How about corrections? Even a comma too few or too many needs the whole line cast over again. It is a convincing proof of the difference in speed between the two methods that a column of type can be corrected much faster by the machine, handicapped as it is by its solid “slugs,” than by hand. No wonder then that more than 1000 linotypes are to be found in the printing offices of Great Britain.
The Monotype, like the Linotype, aims at speed in composition, but in its mechanism it differs essentially from the linotype. In the first place, the apparatus is constructed in two quite separate parts. There is a keyboard, which may be on the third floor of the printing offices, and the casting machine, which ceaselessly casts and sets type in the basement. Yet they are but one whole. The connecting link is the long strip of paper punched by the keyboard mechanism, and then transferred to the casting machine to bring about the formation of type. The keyboard is the servant of man; the casting machine is the slave of the keyboard.
Secondly, the Monotype casts type, not in blocks or a whole line, but in separate letters. It is thus a complete type-foundry. Order it to cast G’s and it will turn them out by the thousand till another letter is required.