y in the wax clear to the metal with a sharp
instrument. Then apply the mixed acids with a feather, carefully filling
each letter. Let it remain from one to ten hours, according to the
appearance desired, throw on water, which stops the process, and remove
the wax.

HOW TO TRANSFER A PHOTOGRAPHIC PRINT TO GLASS.

To transfer a photographic print to glass for painting or for other
purposes, separate the paper print from the background by steaming it; dry
thoroughly, and having given the warmed glass an even coating of clean
balsam or negative varnish, place the face of the print on the surface
thus prepared, smooth it out and let it stand in a cool place until the
varnish has hardened. Then apply water, and with a soft piece of
gum-rubber rub off the paper so as to leave the photographic image on the
varnished glass.

STEREOTYPING WOODCUTS.

In stereotyping woodcuts, care should be taken that they are thoroughly
dry before being sent to the foundry, as the intense heat to which they
are subjected frequently causes them to warp and split, especially if
pierced.

TO GILD WITH GOLD LEAF.

Bookbinders use gold leaf in two ways--to gild on the edge, and to place
gold letters on the binding. To gild on the edge, the edge is smoothly
cut, put in a strong press, scraped so as to make it solid, and the
well-beaten white of an egg, or albumen, put on thinly; the gold leaf is
then put on before the albumen is dry; it is pressed down with cotton,
and when dry polished with an agate polisher. To put on the lettering, the
place where the letters are to appear is coated with albumen, and after it
is dry, the type to be used is heated to about the boiling point of water,
the gold leaf is put on, either on the book or on the type, and then
placed on the spot where the lettering is desired, when the gold leaf will
adhere by the heat of the type, while the excess of gold leaf loosely
around is rubbed off with a tuft of cotton.

GILDING ON WOOD.

To gild in oil, the wood, after being properly smoothed, is covered with a
coat of gold size, made of drying linseed oil mixed with yellow ochre.
When this has become so dry as to adhere to the fingers without soiling
them, the gold leaf is laid on with great care and dexterity, and pressed
down with cotton wool. Places that have been missed are covered with small
pieces of gold leaf, and when the whole is dry the ragged bits are rubbed
off with cotton. This is by far the easiest