"Heating and Ventilation," would be the best. A furnace of
this description is shown in the design for an elaborate private bath,
at Fig. 25. Should the bath be heated regularly every day, a firebrick
furnace is certainly the best, as such furnaces retain their heat a long
time. It should be "banked" at night. A bath only required at times, and
quickly, is best heated with a thin iron stove. A portable iron stove
and a long length of iron flue will rapidly raise the temperature. The
simple baths illustrated at Figs. 22 (A) and 23, are therefore very
convenient and effective. The principle of heating by the transmission
to the hot rooms of freshly-heated air is also a very convenient one for
private purposes, as on this system the bath may be on an upper floor,
and yet have its heating apparatus conveniently stowed away below, as at
Fig. 24. A small furnace chamber, such as that at Fig. 6, _ante_, must
be constructed, and a hot-air flue of large section built up to the hot
room. If the bath be on the ground floor, the construction of any form
of heating apparatus is rendered easier.

To prevent the transmission of heat to other apartments of the house,
the precautions hereinbefore mentioned must be observed. Hollow walls
must be provided round the heated chambers, to prevent loss of heat on
the external side, and the transmission of heat through internal walls.
The floors above and below should--if not of solid fireproof
construction--be formed as described in the section dealing with the
design of the sudorific chambers, with puggings of slag-wool, asbestos,
sawdust, or materials having similar properties. Windows should be
double. Wherever possible, concrete floors should be provided to the hot
rooms and washing rooms, so that they may be covered with tiles or
mosaics, and on account of the spilling of water. It should be needless
to point out the necessity of having most careful regard to safety from
fire by the stoves or furnaces.

The ventilation of private baths should receive as much careful
attention as those for public use. The hollow external walls may often
be used with advantage for the extraction of the vitiated air, which
must be let into the cavity at the floor level. If the bath be
constructed on the ground floor, with nothing beneath, the system of
carrying off the vitiated air by horizontal conduits--recommended for
public baths--should be employed, as in the accompanying design for a
large private ba