enamelling oven heated by hot-water pipes (steel) closed at both ends
and partially filled with water which always remains sealed up
therein, and never evaporates until the pipes require to be refilled.

This stove may be heated (1) by hot-water pipes (iron), (2) by
super-heated water, (3) by steam, but only to 80° C. The different
compartments may be heated to uniform or to different temperatures
with hot water; the stoke-hole is at the side and thus quite separated
from the stove proper.

The ovens must be on the ground floor, so that the super-heated steam
from the basement may be available.

The great drawback to the use of gas for heating japanning and
enamelling stoves is the great cost of coal gas.

[Illustration: FIG. 13.--Portable Gas Heated Japanning and Enamelling
Stove fitted with Shelves, Thermometer, etc.]


PIGMENTS SUITABLE FOR JAPANNING WITH NATURAL LACQUER.

_White Pigments._--Barium sulphate and bismuth oxychloride. These two
are used for the white lacquer or as a body for coloured lacquers.
When the lacquer is to be dried at a high temperature barium sulphate
is preferable, but when it is dried at an ordinary temperature bismuth
oxychloride is better. Since the lacquer is originally of a brown
colour the white lacquer is not pure white, but rather greyish or
yellowish. Many white pigments, such as zinc oxide, zinc sulphide,
calcium carbonate, barium carbonate, calcium sulphate, lead white,