abouts on the left-hand
cheek the point of the knife comes. In a press that is true the knife
should just clear the edge of the press. If there is too much packing
the knife will cut below the edge of the press, and if too little, it
will cut above.

"Packing" is paper inserted between the knife and the metal plate on
the plough, to correct the position of the knife. When by experiment
the exact thickness of paper necessary for any given knife is found,
the packing should be carefully kept when the knife is taken out for
grinding, and put back with it into the plough.

The first edge to be cut is the top, and the first thing to do is to
place the boards in the position they will hold when the book is
bound. The front board is then dropped the depth of the square
required, care being taken that the back edge of the board remains
evenly in the joint. A piece of cardboard, or two or three thicknesses
of paper, are then slipped in between the end paper and the back board
to prevent the latter from being cut by the knife. The book is then
carefully lowered into the press, with the back towards the workman,
until the top edge of the front board is exactly even with the
right-hand cheek, and the press screwed up evenly. The back board
should show the depth of the square above the left-hand cheek. It is
very important that the edge of the back board should be exactly
parallel with the press, and if at first it is not so, the book must
be twisted until it is right.

The edges can now be cut with the plough as in cutting mill-boards.
The tail of the book is cut in the same way, still keeping the back
of the book towards the workman, but cutting from the back board.

[Illustration: FIG. 54.]

[Illustration: FIG. 55.]

Cutting the fore-edge is more difficult. The waste sheets at each end
of the book should be cut off flush with the edge of the board, and
marks made on them below the edge showing the amount of the square,
and consequently how much is to be cut off. The curve of the back, and
consequent curve of the fore-edge, must first be got rid of, by
inserting a pair of pieces of flat steel called "trindles" (fig. 54)
across the back, from the inside of the boards. When these are
inserted the back must be knocked quite flat, and, in the case of a
heavy book, a piece of tape may be tied round the leaves (see fig. 55)
to keep them in position. A pair of cutting boards is placed one on
each side of the leaves, the b