Since the method of heating by means of hollow floors only came into vogue about 100 B.C., and since the duumvirate of Ulius and Aninius must have occurred soon after 80 B.C., we are probably safe in supposing that they built the hollow floors of the two caldariums, and that the new heating arrangement was loosely called a Laconicum. At least a partial warrant for this interpretation is found in a passage of Dion Cassius (LIII. xxvii. 1), in which he says that Agrippa built the 'Spartan sweating bath,' τὸ πυριατήριον τὸ Λακωνικόν. Agrippa, however, built, not a Laconicum in the narrow sense, but a complete bathing establishment, and Dion, doubtless following some earlier writer, uses the word as generally applicable to a system of warm baths. In default of a better explanation, we must accept a meaning equally loose for our inscription. It is not possible to date, even approximately, the other changes by which the baths were conformed to the increasing desire for warmth and comfort; but the decoration of the greater part of the building, with its complicated designs and stucco reliefs, was clearly applied to the walls not many decades before the destruction of the city. The unroofed swimming tank, F, was separated from the court by a barrier of masonry about two feet high, which was extended also in front of the rooms at the ends, E and G. On either side was a step, both the steps and the barrier being veneered with white marble. The tank was supplied by a pipe entering from the northeast; the overflow pipe, at the southeast corner, is indicated on the plan. The rooms E and G, opening both on the swimming tank and on the court with high arched doorways, were roofed shallow basins where the athletes could give themselves a preliminary cleaning before going into the tank. The walls are veneered with marble to a height of 6½ feet; above are painted plants, birds, statues, and nymphs, one of whom holds a shell to catch a jet of water; over these the blue sky. Here, as in the frigidarium, the artist strove to convey the impression of being in the open air, in a beautiful garden, adorned with sculptures. A jet of water spurted from the rear wall just above the marble dado; above it is a large oblong niche, apparently for a statue. After a time the basin in G was filled up, and covered with a mosaic floor of the same height as the threshold; when one cleaning room was found to be adequate, that was retained which had a separate dressing room, D. On the white walls of the dressing room are traces of the wooden wardrobes that once stood against them. In this room, the destrictarium, the athletes disrobed, and rubbed themselves with oil before engaging in gymnastic exercises, and to it they returned from the palaestra, in order to scrape themselves (_se destringere_); then they washed themselves in the next room, E, and finally plunged into the tank.