rawn from the same area. On the ground floor are cooling and
dressing rooms; the bath rooms are in the basement and the furnace in a
sub-basement, reached from a passage at the end of the stairs for the
bather. Two convoluted stoves are shown in a vault; three air-inlets are
provided, and the foul air is drawn up into the smoke flues, two in
number, which, above, could join one another. Let us follow the air in
its passage through the bath. Entering at the intakes, any coarse
impurities are thrown off by the smooth louvres, and the tendency of
finer particles to rush in is checked by the stretched canvas
cheese-cloths. Thus deprived of its actually visible impurities, the air
passes through a longer or shorter conduit of glazed brickwork until it
reaches the horizontal flues running to beneath the furnace walls, along
which it is rapidly drawn, and, ascending between the walls and heating
surfaces and between the two adjacent heating surfaces, absorbs the
radiating heat and enters the laconicum by way of the rectangular shaft
constructed above the vault spanning the two stoves.

Questions of temperature I will omit for the present. The air, on
passing through the laconicum, will be practically pure, as it is in
such great bulk compared with the number of occupants of this
highly-heated chamber, and it will not be absolutely necessary to
provide ventilators. These should commence in the calidarium, and
should, in the scheme of ventilation here considered, be so disposed
that the nearer they are to the lavatorium and shampooing-room, the more
frequent will they become. The object of this disposition of outlets for
vitiated air is, that the cross currents thus created may not interfere
with the main flow from the heating chamber to the lavatorium. Were too
many ventilators to be placed near the hotter end of the sudatorium,
this stream would be diverted. Too much of the freshly-heated air would
flow out at these points, and the onward movement of the air would be
enfeebled. There would then be difficulty in maintaining the temperature
in the tepidarium and lavatorium.

In passing onward through the various rooms, two changes are wrought in
the air: it loses so much of the caloric with which it is charged for
every foot it travels, and it becomes laden with the exhalations from
the lungs of the bathers. A large proportion of carbonic acid is thrown
into the air, and as the normal temperature of the human body remains,
in a