mount to leave here must be decided by the thickness of the
boards to be used. When the backing boards are in position, the book
and boards must be carefully lowered into the lying press and screwed
up very tight, great care being taken to see that the boards do not
slip, and that the book is put in evenly. Even the most experienced
forwarder will sometimes have to take a book out of the press two or
three times before he gets it in quite evenly and without allowing the
boards to slip. Unless the back has a perfectly even curve when put in
the press for backing, no amount of subsequent hammering will put it
permanently right.

[Illustration: FIG. 40.]

[Illustration: FIG. 41.]

The backs of the sections should be evenly fanned out one over the
other from the centre outwards on both sides. This is done by side
strokes of the hammer, in fact by a sort of "riveting" blow, and not
by a directly crushing blow (see fig. 41, in which the arrows show the
direction of the hammer strokes). If the sections are not evenly
fanned out from the centre, but are either zigzagged by being crushed
by direct blows of the hammer, as shown in fig. 42, A, or are unevenly
fanned over more to one side than the other, as shown in fig. 42, B,
the back, although it may be even enough when first done, will
probably become uneven with use. A book in which the sections have
been crushed down, as at fig. 42, A, will be disfigured inside by
creases in the paper.

[Illustration: FIG. 42.]

[Illustration: FIG. 43.]

[Illustration: FIG. 44.]

It is a mistake to suppose that a very heavy hammer is necessary for
backing any but the largest books. For flexible books a hammer with a
comparatively small face should be used, as by its use the book can be
backed without flattening the bands. It is well to have a hammer head
of the shape shown in fig. 43. By using the thin end, the force of a
comparatively light blow, because concentrated on a small surface, is
effective.

At fig. 44 is shown an ordinary backing hammer.

CHAPTER IX

Cutting and Attaching Boards--Cleaning off Back--Pressing

CUTTING AND ATTACHING BOARDS

The first quality of the best black board made from old rope is the
best to use for "extra" binding. It will be found to be very hard, and
not easily broken or bent at the corners. In selecting the thickness
suitable for any given book, the size a