Page:The Art of Bookbinding, Zaehnsdorf, 1890.djvu/91

Rh "bolt knife" and "slide knife." The forwarder will find that the latter is preferable, on account of its facility of action, as any length of knife can be exposed for cutting. But with a bolt knife, being fastened to the shoe of the plough, it is necessarily a fixture, and must be worn down by cutting or squaring mill-boards, or such work, before it can be used with the truth necessary for paper.

To cut a book properly it must be quite straight, and the knife must be sharp and perfectly true. Having this in mind, the book may be cut by placing the front board the requisite distance from the head that is to be cut off. A piece of thin mill-board or trindle is put between the hind board and book, so that the knife when through the book may not cut the board. The book is now to be lowered into the cutting press, with the back towards the workman, until the front board is exactly on a level with the press. The head of the book is now horizontal with the press, and the amount to be cut off exposed above it. Both sides should be looked to, as the book is very liable to get a twist in being put in the press. When it is quite square the press is to be screwed up tightly and evenly. Each end should be screwed up to exactly the same tightness, for if one end is loose the paper will be jagged or torn instead of being cut cleanly.

The book is cut by drawing the plough gently to and fro; each time it is brought towards the workman a slight amount of turn is given to the screw of the plough. If too much turn is given to the screw, the knife will bite too deeply into the paper and will tear instead of cutting it. If the knife has not been properly sharpened, or has a burr