ords are corrected. Then the proof goes to
the author, who makes any changes in his part of the work which seem
to him desirable; and it is also read by some member of the editorial
department. If there are many changes to be made, another proof is
usually taken and sent to the author.

The reason for this extreme carefulness is that it costs much less to
make changes in the galley proof than in the "page proof." This latter
is made by dividing the galley into pages, leaving space for the
beginnings of chapters and for pictures, if any are to appear on the
printed pages, and setting up the numbers of the pages and their
running titles. Page proof also goes to proof-readers and to the
author. Corrections on page proof are more expensive than on galley
proof because adding or striking out even a few words may make it
necessary to change the arrangement on every page to the end of the
chapter.

Years ago all books were printed directly from the type; and some are
still printed so. After printing, the letters were returned to their
compartments. If a second edition was called for, the type had to be
set again. Now, however, books are generally printed not from type,
but from a copper model of the type. To make this, an impression of
the page of type is made in wax and covered with graphite, which will
conduct electricity. These moulds are hung in a bath of copper
sulphate, where there are also large plates of copper. A current of
electricity is passed through it, and wherever the graphite is, a
shell of copper is deposited, which is exactly like the face of the
type. This shell is very thin, but it is made strong by adding a heavy
back of melted metal. From these plates the books are printed. A
correction made in the plate is more expensive than it would have been
if made in the galley or in the page, because sawing out a word or a
line is slow, delicate work; and even if one of the same length is
substituted, the types spelling it have to be set up, a small new
plate cast, and soldered in.

[Illustration: _Courtesy The Riverside Press._

WHERE THIS BOOK WAS PRINTED

The girls are feeding big sheets of paper into the presses, thirty-two
pages being printed at one time. The paper is fed into many modern
presses by means of a machine attached to the press. The pressmen see
that the printing is done properly.]

Printing one page at a time would be altogether too slow; therefore
the plates are arranged in such a way tha