ublic baths. 24. Caldarium.
It might, however, be employed at pleasure as a tepid or cold bath,
when the weather was too cold for bathing in the open air. The
suspensura caldariorum, as Vitruvius calls the hollow walls and floors
raised upon pillars, are in remarkably good preservation. By means of
these the whole apartment was entirely enveloped in flame, and might
be easily raised to a most stifling temperature.

We will, however, add that Vitruvius directs a bed of clay mixed with
hair to be laid between the pillars and the pavement; and some
tradition of this custom may be imagined to subsist, for the potters
of the country, in some cases, work up wool with their clay, a
practice unknown elsewhere, as we believe, in the art of pottery. The
burning vapor passed out above the ceiling, gaining no entrance into
the apartment. Air and light were admitted by two windows, one higher
than the other. In one of these Mazois found a fragment of glass. The
bathing-vessel, _e_, lined with stucco, and coated on the outside with
marble, was fed by two cocks, which must have been very small, to
judge from the space which they occupied. Hence, hot and cold water
were supplied at pleasure; and it was only to fill the vessel with
boiling water, and the whole apartment would be converted into one
great vapor bath.

As it would have been difficult or impossible to have kept alive a
lamp or torch in so dense a steam, there is near the door a circular
hole, closed formerly by a glass, which served to admit the light of a
lamp placed in the adjoining chamber. The hypocaust, or furnace and
apparatus, 25, for heating the water, are so placed that they can not
be seen from the triangular court. They are small, but correspond with
the small quantity of boiling water which they were required to
furnish. _f._ Stone table. _g._ Cistern. _h._ Mouth of hypocaust. _i._
A furnace, probably for boiling water when merely a tepid bath was
required, without heating the suspensura caldariorum. By the side of
the hypocaust were placed the vases for hot and cold water, as
described in the chapter on Baths; their pedestals were observable
between the mouth of the furnace and the letter _k._ _l._ Wooden
staircase, no longer in existence, which led to the apartments above.
26. Reservoir.

Such was the distribution of this bath. Some paintings and mosaics,
which are ordinary enough, formed its only decorations; yet, from the
little that remains, we can disc