, such as _l_, _f_, or _t_, are apt to slip
out of place at the ends of lines. And here a serious source of error
may be mentioned which can be found out only by reading the whole page
over. In type set on the linotype machine every line is one solid
piece of metal. Any correction to be made involves resetting the whole
line. Now the compositor in inserting the new line is very apt to take
out a line _beginning with the same word_, replacing it with the new
one, thus making a very serious blunder, and of course the
proof-reader or author who sees the next proof has no intimation that
the wrong line has been tampered with. On reading the page over,
however, it will be noticed that something is wrong, previous proofs
can be referred to, and the mistake rectified.

The proofs having been finally read, revised, and marked O. K., the
pages are sent to the foundry or to press, as the case may be.

But the proof-reader has not done with them yet. If the book is
electrotyped, the plates may turn out faulty; sometimes the type will
sink in places under the enormous pressure applied in moulding. It is
therefore highly advisable that proofs should be taken of the plates
and gone over for imperfections; this may save valuable time later
when the book is on the press. Some authors don't mind the expense of
making changes in their work even after the pages are cast.

The proof-reader only takes leave of the book when it is on the press
and all is ready to go ahead and print. A sheet is submitted to him
which he must _vise_ for bad letters, see that nothing has fallen out
in transit to the pressroom, and that the pressman has not taken out
any cuts to underlay and reinserted them upside down. He will also
verify the folios again (if the book is printed from plates this will
be the first opportunity of doing so) and see that the pages join up
to what has gone before. Here his work ends.

PAPER MAKING

By Herbert W. Mason.

The word "paper" derives its name from the ancient Greek word
"papyrus," the name of the material used in ancient times for writing
purposes, and manufactured by the Egyptians from the papyrus plant,
and which was, up to the eighth century, the best-known writing
material. Probably the earliest manufacturers of paper were the
Chinese, who used the mulberry tree and other like plants for this
purpose, and may be called the inventors of our modern paper
manufacturing, as they have practised the art of pa