om the middle pass it to the other
end, taking care that before each stroke the brush be well supplied
with varnish; when one coat is dry another must be laid over it in
like manner, and this must be continued five or six times. If on trial
there be not a sufficient thickness of varnish to bear the polish
without laying bare the painting or ground colour underneath more
varnish must be applied. When a sufficient number of coats of varnish
is so applied the work is fit to be polished, which must be done in
common work by rubbing it with a piece of cloth or felt dipped in
tripoli or finely ground pumice-stone. But towards the end of the
rubbing a little oil of any kind must be used with the powder, and
when the work appears sufficiently bright and glossy it should be
well rubbed with the oil alone to clean it from the powder and to give
it a still greater lustre. In the case of white grounds, instead of
the tripoli, fine putty or whiting should be used, but they should be
washed over to prevent the danger of damaging the work from any sand
or any other gritty matter that may happen to be mixed with them. It
greatly improves all kinds of japan work to harden the varnish by
means of heat, which, in every degree that can be applied short of
what would burn or calcine the matter, tends to give it a firm and
strong texture where metals form the body; therefore a very hot stove
may be used, and the stoving may be continued for a considerable time,
especially if the heat be gradually increased. But where wood or
papier-mache is in question, heat must be applied with great caution.

SECTION III.

JAPANNING OR ENAMELLING METALS.

In japanning metals, all good work of which should be stoved, they
have to be first thoroughly cleaned, and then the japan ground applied
with a badger or camel-hair brush or other means, very carefully and
evenly. Metals usually require from three to five coats, and between
each application must be dried in an oven heated from 250 deg. to 300 deg.
F.--about 270 deg. being the average. It has already been seen that the
best grounds for japanning are formed of shellac varnish, the
necessary pigments for colouring being added thereto, being mixed with
the shellac varnish after they have been ground into a high degree of
smoothness and fineness in spirits of turpentine. In japanning it is
best to have the oven at rather a lower temperature, increasing the
heat after the work has been placed in the