Plan of the Old Baths at Pompeii
A public bath was built around three principal rooms: the caldarium (hot bath), the tepidarium (warm bath) and the frigidarium (cold bath). Some thermae also featured steam bath, a moist steam bath, a dry steam bath much like a modern sauna.
By way of illustration, this article will describe the layout of Pompeii's Old Baths adjoining the forum, which are among some of the best-preserved Roman baths.
The whole building comprises a double set of baths, one for men and the other for women. It has six different entrances from the street, one of which gives admission to the smaller women's set only. Five other entrances lead to the men's department, of which two, communicate directly with the furnaces, and the other three with the bathing apartments.
Atrium
Passing through the principal entrance, which is removed from the street by a narrow footway surrounding the building and after descending three steps, the bather finds a small chamber which contained a water closet (latrina), and proceeds into a covered portico, which ran round three sides of an open court. These together formed the vestibule of the bath, in which the servants waited.
Use of the atrium
This atrium was the exercise ground for the young men, or perhaps served as a promenade for visitors to the baths. Within this court the keeper of the baths (balneator), who exacted the quadrans paid by each visitor, was also stationed. One room, which runs back from the portico, might have been appropriated to him; but most probably it was an oecus or exedra, for the convenience of the better classes while awaiting the return of their acquaintances from the interior. In this court, advertisements for the theatre, or other announcements of general interest, were posted up. At the sides of the entrance were seats (scholae).
Apodyterium
A passage (s) leads into the apodyterium, a room for undressing in which all visitors must have met before entering the baths proper. Here, the bathers removed their clothing, which was taken in charge by slaves known as capsarii, notorious in ancient times for their dishonesty. The apodyterium was a spacious chamber, with stone seats along two sides of the wall. Holes are still visible on the walls, and probably mark the places where the pegs for the bathers' clothes were set. The chamber was lighted by a glass window, and had six doors. One of these led to the tepidarium and another to the frigidarium, with its cold plunge-bath.
Tepidarium
From the frigidarium the bather who wished to go through the warm bath and sweating process entered the tepidarium. It did not contain water either at Pompeii or at the baths of Hippias, but was merely heated with warm air of an agreeable temperature, in order to prepare the body for the great heat of the vapor and warm baths, and, upon returning, to prevent a too-sudden transition to the open air. In the baths at Pompeii this chamber also served as an apodyterium for those who took the warm bath. The walls feature a number of separate compartments or recesses for receiving the garments when taken off. The compartments are divided from each other by figures of the kind called Atlantes or Telamones, which project from the walls and support a rich cornice above them.
Three bronze benches were also found in the room, which was heated as well by its contiguity to the hypocaust of the adjoining chamber, as by a brazier of bronze (foculus), in which the charcoal ashes were still remaining when the excavation was made.
The tepidarium is generally the most highly ornamented room in baths. It was merely a room to sit in and be anointed in. In the Old Baths at Pompeii the floor is mosaic, the arched ceiling adorned with stucco and painting on a coloured ground, the walls red.
Anointing was performed by slaves called unctores and aliptae. It sometimes took place before going to the hot bath, and sometimes after the cold bath, before putting on the clothes, in order to check the perspiration. Some baths had a special room (destrictarium or unctorium) for this purpose.
Caldarium
From the tepidarium a door opened into the caldarium , whose mosaic floor was directly above the furnace or hypocaust. Its walls also were hollow, forming a great flue filled with heated air. At one end was a round basin (labrum), and at the other a quadrangular bathingplace (puelos, alveus, solium, calida piscina), approached from the platform (schola) by steps. The labrum held cold water, for pouring upon the bather's head before he left the room. These basins are of marble in the Old Baths, but also made of alvei of solid silver. Because of the great heat of the room, the caldarium was but slightly ornamented.
Service
The apodyterium has a passage communicating with the mouth of the furnace, called praefurnium or propigneum; and, passing down that passage, we reach the chamber, into which the praefurnium projects, and which is entered from the street at. It was assigned to the fornacatores, or persons in charge of the fires. Of its two staircases, one leads to the roof of the baths, and one to the boilers containing the water.
There were three boilers, one of which (caldarium vas) held the hot water; a second, the tepid (tepidarium); and the third, the cold (frigidarium). The warm water was turned into the warm bath by a pipe through the wall, marked on the plan. Underneath the hot chamber was set the circular furnace, of more than 7 ft. in diameter, which heated the water and poured hot air into the hollow cells of the hypocaustum. It passed from the furnace under the first and last of the caldrons by two flues, which are marked on the plan. The boiler containing hot water was placed immediately over the furnace; and, as the water was drawn out from there, it was supplied from the next, the tepidarium, which was raised a little higher and stood a little way off from the furnace. It was already considerably heated from its contiguity to the furnace and the hypocaust below it, so that it supplied the deficiency of the former without materially diminishing its temperature; and the vacuum in this last was again filled up from the farthest removed, which contained the cold water received directly from the square reservoir seen behind them. The boilers themselves no longer remain, but the impressions which they have left in the mortar in which they were imbedded are clearly visible, and enable us to determine their respective positions and dimensions. Such coppers or boilers appear to have been called miliaria, from their similarity of shape to a milestone. Behind the boilers, another corridor leads into the court or atrium appropriated to the servants of the bath.
Women's bath
The adjoining, smaller set of baths were assigned to the women. The entrance is by the door, which conducts into a small vestibule and from there into the apodyterium, which, like the one in the men's bath, has a seat (pulvinus, gradus) on either side built up against the wall. This opens upon a cold bath, answering to the natatio of the men's set, but of much smaller dimensions. There are four steps on the inside to descend into it.
Opposite to the door of entrance into the apodyterium is another doorway which leads to the tepidarium, which also communicates with the thermal chamber, on one side of which is a warm bath in a square recess, and at the farther extremity the labrum. The floor of this chamber is suspended, and its walls perforated for flues, like the corresponding one in the men's baths. The tepidarium in the women's baths had no brazier, but it had a hanging or suspended floor.
