As a rule, not more than six urinals should be flushed from one cistern on account of the difficulty of distributing the water equally to all the stalls. A common arrangement consists in fixing the cistern over the centre of the range, and connecting the down-pipe to a horizontal pipe from which a branch is taken to each stall.

Fig. 148. Nicholls and Clarke's Automatic Flushing Cistern for Urinals.

The ends of the horizontal pipe may with advantage be curved upwards beyond the extreme branches, as this reduces the concussion caused by the flush. Another arrangement, shown in fig. 149, may be used for ranges of three to six stalls, and ensures a more equal flush throughout the range. The pipes may be of lead or copper, and the diameter must be regulated by the capacity of the cistern, but is not generally less than J in.

Perforated copper sparge-pipes have been largely used for flushing stall-urinals, but are not very satisfactory; splashing frequently occurs and some of the holes become choked, so that a large part of the surface is often not touched by the water. Iron sparge-pipes are soon destroyed by corrosion. In more recent stall-urinals with curved backs a distributing nozzle is adopted, which is simply a short tube with closed end and with a transverse slit cut obliquely in the lower half; this gives an excellent flush, and distributes the water over the whole of the curved surface below the nozzle. It is also much neater and cleaner than a sparge-pipe. Care should be taken that the nozzle is of such a type that it can be removed without disturbing the urinal.

Fig. 149. Flush-pipes for a Range of Urinals.

Public Urinals above ground are often constructed of cast-iron, but frequent painting is required to retard the inevitable corrosion caused by the ammonia and water.

Sometimes such urinals are constructed of vertical slabs of slate with grooved edges into which iron tongues are fitted, but the shoulders of the grooves are soon burst off by frost and by the corrosion of the iron.

Urinettes

"Urinette" is the name given to a fitting intended for ladies' use. These have been occasionally fixed in ladies' public conveniences, as they occupy less space than water-closets, although they are made on the same general lines. In the underground conveniences in Shoreditch the space allotted to each urinette is 2 ft. 3 in. by 2 ft. 9 in.; the divisions between them are of marble, and a waterproof curtain is hung in front of each basin. The urinette is practically a wash-down closet, with a fixed seat, which is all the better if the front portion is entirely cut away. A range of urinettes may be flushed from a single automatic cistern.