m, forty
parts of English glue, ten parts of albumen, two parts of glacial acetic
acid, ten parts of alcohol of 60 deg., and 500 parts of water. It is
afterwards put into a second bath, which contains fifty parts of burnt
umber ground in alcohol, twenty parts of lampblack, ten parts of English
glue, and ten parts of bichromate of potash in 500 parts of water. They
are now sensitive to light, and must, therefore, be preserved in the dark.
In preparing paper to make the positive print, another bath is made just
like the first one, except that lampblack is substituted for the burnt
umber. To obtain colored positives the black is replaced by some red,
blue, or other pigment.

In making the copy, the drawing to be copied is put in a photographic
printing frame, and the negative paper laid on it, and then exposed in the
usual manner. In clear weather an illumination of two minutes will
suffice. After the exposure the negative is put in water to develop it,
and the drawing will appear in white on a dark ground; in other words, it
is a negative or reversed picture. The paper is then dried and a positive
made from it by placing it on the glass of a printing frame, and laying
the positive paper upon it, and exposing as before. After placing the
frame in the sun for two minutes, the positive is taken out and put in
water. The black dissolves off without the necessity of moving back and
forth.

WASHING FORMS.

Forms sent down to machine ought not to be wet too much with lye or with
water, otherwise it becomes necessary to dry them before working, which
takes time and often much trouble. The wet works up little by little to
the face of the letter, and then the form becomes unworkable. It has often
to be taken off the coffin, the feet of the types have to be thoroughly
dried, then some sheets of unsized paper have to be placed under the form;
it has also to be unlocked, shaken, locked up again, the sheets removed
with the moisture they have imbibed, and then it is to be hoped the form
will be workable. If not there is nothing to be done but to lift it and
dry it by heat.

Lye is generally used for washing forms which do not contain wood blocks;
turpentine where wood-cuts or wood-letters are to be found in them. The
bristles of the lye-brush should be longer than those of the
turpentine-brush, and, in order to preserve it, each brush should be
properly washed with water after using, and shaken and stood up to dry. If
this is no