end, worked with an iron lever. Into
this press the books were clamped, the rough edge to be trimmed off
projecting above the jaws. To trim the book, a plough was used, made
of two thick side pieces of hard wood about one foot long and six
inches high, with a long hand screw passing through them. (The end at
the right had a handle outside of the side piece, and the end at the
left engaged a screw in the left side piece.) At the bottom of the
right side piece, and resting on the jaw of the press, was a
sharp-pointed knife. The plough was worked back and forth, and at each
motion the screw in the plough was turned enough for the knife to
take a shaving from the book. To keep the plough in place, the
left-hand jaw had a deep groove on its surface, in which the plough
worked. This was slow and hard work.

Sometime between the years 1840 and 1850, a machine was invented in
which books were clamped, and a heavy knife descended perpendicularly.
This was an improvement on the old-fashioned press and plough, but it
was found that, unless the knife was very sharp, the tendency was to
draw the paper, and in effect jam it off rather than cut it.

To obviate this, the next move was to arrange the knife so that it
would give a drawing cut, or come down on a slant, rather than a rigid
descent. This is the principle on which most book and paper cutting
machines are made to-day.

About 1850 a machine was invented in which a vibrating knife worked
back and forth on the paper to be cut. This was thought at the time to
be the best principle for a cutting machine.

Ten or twenty years later a new machine made its appearance. This one
had a knife held rigidly in the frame of the machine, and the books
were clamped into a carriage drawn up by a chain against the edge of
the knife. It was the most rapid trimmer that had appeared, and held
its position for a good many years; but in the meantime, for general
work, the machines with a descending slanting knife held their own and
multiplied.

Within a very short time a new machine has appeared. This has two
slanting descending knives and doubles the work of the older machines,
as it cuts two sides at one blow, and will trim from 7000 to 8000
ordinary books a day, against 500 or 600 by the old-fashioned press
and plough.

After the edges are trimmed, the book is rounded and backed. In this
process, too, great improvement has been made. Originally this work
was done by hand with a hammer, t