this purpose are always built on hill sides, and are joined together,
increasing in size from the lower to the higher ones, and in number from
four to twenty five; these kilns are so constructed that the draught is
from the lowest one, in addition to which each kiln has its own firing
place. The result of this construction is that the upper ones are by
far the most heated, and the ware is arranged accordingly; that which
requires the least baking, in the lower kiln, and that which requires
the greatest heat, in the upper. These connecting kilns have the merit
of being heat saving, but they are usually small and badly constructed,
and the heat in none of them is uniform.

The glaze is made from the silicious clay and potash extracted from wood
ashes. This potash is not a pure white, and this accounts for the dirty
color usually to be observed in unpainted Japanese ware. In different
districts the painting varies. For instance, in Owari, the greater part
of the ware is painted a cobalt blue--the cobalt ore being found in the
bluffs near the clay deposits, and is used for painting the cheaper
wares, and for this purpose German cobalt is also employed. The painting
with cobalt is generally done on the biscuit before glazing. In several
districts a very handsome ware is made, and painted on the glaze. For
this kind of painting the colors are mixed with a silicate of lead
and potash, and baked the third time in a small furnace at a low
temperature. The coloring oxides in use are those of copper, cobalt,
iron, antimony, manganese, and gold. Japanese porcelain painting may be
divided into two categories, decorative and graphic; the first is used
to improve the vessel upon which it is placed, and this class includes
all the ware except that of the province of Kaga, which would come under
the head of graphic, as it delineates all the trades, occupations,
sports, customs, and costumes of the people, as well as the scenery,
flora, and fauna of the country. "Owari ware" is made in the province