The plunge bath is at times a source of two difficulties--it may leak, and it may be below the level of drain. The first evil is the result of an error in design, or of bad workmanship; the latter is unavoidable. The following method of constructing a plunge bath has been adopted with perfect success:--On the bed of concrete prepared for its floor, erect side walls of concrete, and on the floors and walls thus formed spread two distinct layers of asphalt, covering all and running up to the underside of coping. Against the sides build half-brick walls in cement, with glazed face, and lay the floor with glazed bricks flat. The general principles of this construction I show in the accompanying illustration. Where the bath is lower than the drain, all that can be done is to drain out as much as possible and pump the remaining water from a "sump" provided in a suitable position. By raising the plunge bath chamber a few feet, the bottom of bath may, in some cases, be just kept above the drain level; but steps must then be placed between it and the washing-room, and steps in such places are dangerous, being very liable to become slippery. [Illustration: FIG. 4.] [Illustration: A Plunge Bath.] THE FRIGIDARIUM OR COOLING ROOM, AND DRESSING ACCOMMODATION FOR BATHERS. Dressing and cooling accommodation in a public bath may be provided in one of the following ways:--1. A separate frigidarium and distinct dressing room, arranged (_a_) in direct communication with one another, or (_b_) connected by a lobby, corridor, or ante-room;--2. A combination apartment arranged (_a_) with dressing-boxes around the walls, and couches in the centre, or _vice versâ_; (_b_) with Oriental divans; (_c_) with couches screened off in pairs or singly by dwarf wood screens; (_d_) with a few private dressing-boxes, a few couches, and a few lounges, and easy cushioned chairs; and (_e_) as a simple room with couches placed therein, by the side of which the bather will undress, and on which he will recline after his bath. The first of these arrangements may be admirably adapted to unpretentious establishments, where, however, it is wished to employ separate rooms; the second (1, _b_) is only suitable for elaborate baths of the highest class, in which it may be adopted with excellent and with practical results. Of the combination arrangements (_a_) has little to recommend it; (_b_) is expensive and extravagant of space, though it may be made very effective in appearance and very pleasing and comfortable; (_c_) is suitable for ladies' baths; (_d_) is very practicable, and gives the apartment a pleasant, homely look; and (_e_) is best for cheap baths, being the simplest arrangement possible, wholly unsuited, however, to establishments of any pretension.