A good width is also required, so that several can start in a race at the same time. Water-polo, which has done much to popularise swimming, requires a good width for the field of play, and also a good depth of water. The depth usually varies ; one end should be 7 ft., and the other 3 ft. 6 in. in depth. The bath should be lined with white glazed bricks, and have a handrail all round, with a spray at one end and a scum-trough at the other, to take the dust, &c., of the surface of the water.
The hall in which the swimming bath is placed is con structed so much wider to allow of a gangway and dressing boxes, which are usually arranged along the two sides of the bath. The boxes may be 3 ft. 9 in. by 3 ft. 9 in., and the gangway in front 4 ft. 6 in. to 5 ft. in width. There should be a 6-ft gangway at the shallow end of the bath, where the en trance is best made.
The diving stages and spring-boards are placed at the deep end, where there should be a gangway of io feet.
A good gallery, usually continued round the sides of the bath, must be provided to accommodate a large number of spectators. This should be arranged so that all can see the surface of the water. But the best plan of all, if space can be obtained, is to arrange the seats in amphitheatre form and place the dressing-boxes underneath the staging.
A warm and cold shower should be provided ; at the deep end for preference.
The sanitary conveniences should not be placed in direct connection with the bath-houses, but should have a ventilated lobby between ; if this is not done, the tendency is, whatever precautions are taken, for them to ventilate themselves into the bath-house.
The bath-house should be well lighted from the roof by a ridge skylight running the whole length of the building, and there should be clerestory windows on either side if obtainable.
The height of the roof should be carefully considered, and it may be constructed either of wood or iron, or both combined.
Great care should be taken in the proper ventilation of the bath-house.
If the bath-house is to be used as a public hall during a portion of the year, the dressing boxes should be made so that they are removable, a movable floor will have to be provided to cover the bath, and provision must be made for storage when not in use Extra exit must also be provided, and stone staircases arranged from the gallery.
No gallery is required in the second-class bath, and the dimensions of the gangway and boxes, as well as the height of the roof, can be less than in the first-class bath. Although not usual, the second-class bath should in most instances be larger than the first, but as it will be little used for racing, &c., the length and width are not of so much importance as the providing of the largest amount of accommodation possible.
In the women's bath the accommodation should be some what similar to the first-class men's, with a gallery. The length of the bath should not be less than 6o ft., and it should be of a good width, so that water-polo can be played in it.
The subject of heating and maintaining the heat of the water in swimming baths is most important, and in almost every establishment there is an unnecessary waste of water and fuel. As water is a most expensive item, costing from four pence to one shilling per r,000 gallons by metre, the limitation of the necessity for frequently changing and reheating the first supply is of the utmost importance. A simple but noisy system is to inject jets of live steam directly into the swimming bath by means of a finely perforated pipe inserted usually at the bottom of the deep end, the two ends of the pipe returning round and running a few feet along the sides towards the shallow end. The steam is communicated by a pipe running down the side in the middle of the deep end, which has to be protected to prevent bathers being scalded.
A much more elaborate and expensive system, which pro vides for sending the water into the bath at the required tem perature, has been used in one or two large establishments. This is done by passing the water from the main through a heater, which is connected with a patent boiler, and admitting the water at the bottom of the deep end of the bath.
Another system is that for which it is claimed that the whole of the heat generated is used, a uniform temperature ensured, and the waste of water prevented. The water can be dis charged direct into the bath at its normal temperature, then circulated and warmed, or it can be warmed before it is sent into the bath. When the water is once in the bath, it can be constantly circulated, warmed, aerated, and purified. It is with drawn from the top and forcibly returned through patent spreaders placed at equal distances apart over the floor of the bath. By this method the water is heated uniformly, thereby doing away with the cold patches of water which are so fre quently to be found in baths heated by some of the other systems. The cost of heating is also reduced to a minimum, as cold water need not be introduced into the bath so frequently.
No matter what system of heating is adopted, all the pipes, both for hot and cold water, should be placed in a subway, or in such a position as to be easily attended to if repairs are necessary.