Of late years, direct-flushing valves of many forms have been a feature of water-closet design. These valves make the individual closet tank unnecessary. Direct-flushing closets, a type of which is shown in Fig. 44, have the same advantage as the low tank in the matter of being placed where high closets cannot conveniently be arranged. A check to their more general adoption has been the lack of large supplies in residences and other buildings.
The possibility that the house system of water supply may be contaminated from the water-closet if the water supply is directly connected to the water-closet fixture, should not be overlooked. Al though this contamination is more likely to take place in the Operation of the older types of closets, such as the pan closet and the plunger type, it is not of rare occurrence in connection with later types, espe cially the so-called frost-Fool fixture. If the pressure is materially lowered in the street main by accident or otherwise, it sometimes happens that water may be drawn back into the house system by siphonage from a water-closet or like fixture, thus of course incurring the possibility that germs of disease may be brought into the water supply used for domestic purposes. The use of a tank into which the water is first drawn, obviates this danger.
The ordinary dwelling or storehouse supply can be made to operate successfully by placing an accumulating chamber on the branch to the closet, and having a check-valve on the street side of it, so that the water cannot flow back when the pressure falls as a result of drawing at other points. In such cases the pipe between the accumulator and the closet must be the usual 1k-inch size. Closets thus fitted are really only pressure-tank closets with the flush con trolled by a direct-flushing valve to be operated at will instead of automatically by seat-action.
In all tank installations, the direct method is easily employed by carrying the proper size flush main directly to the closets, independ ently of the supply for other fixtures. This is recommended in buildings having numerous closets. One tank, with large flushing main, will serve all the closets, and the individual tanks and equipment are not needed. Furthermore, no trouble is then experi enced in providing suitable space for the small tanks. The flushing valves may, if desired, be placed out of sight, and only the operating lever brought to view in a convenient position. A flushing valve has been made which, like the secondary-valve ball cock, works on the old Jennings diaphragm principle, using a "time" filling cup to establish the initial pressure over the diaphragm. Releasing the pressure over
the diaphragm by means of the operating lever, opens the main channel and causes the closet to flush while the time chamber fills again.
In this country and most others, the height of closets has always been uniformly 16 to 17 inches to top of seat. It is claimed that this height results in an unnatural position, and individual opinions against it have been voiced from time to time with little effect. Lately, however, more earnest attention has been given the subject of height, and there has been designed a closet considerably lower than usual, with the top sloping down toward the back. This form, it is said, induces the user to assume an upright position of body, relatively more closely conforming to that of the limbs, and favoring unrestricted ac tion of the intes tines. It re mains to be seen whether this form will result in any general departure from the old lines.
Closets of ten also serve as urinals, espe cially in private houses. For lim ited service, this is not to be con sidered an actual abuse of the fix ture, though gen eral use of dis tinct urinal fix tures is indispen sable.
Range Clos ets. Batteries of individual clos ets are usual in office buildings and many other such structures; but in schools and in many public places open to all class es„ ranges di vided into stalls or compart ments have been considered a satisfactory solution of the problem.
The objections to the range type of fixture are inherent in the design. The fouling surface of a trough fixture is much greater than that of the number of individual closets to which the fixture corre sponds, and certain parts of this surface are not subject to an adequate flushing action. A certain portion of the surface, much larger relatively than that in individual fixtures, is exposed to spattering with the filth, and is alternately wet and dry. It is also true that the method of applying the water for scouring purposes is much less satisfactory than with single closets. A further objection to the range fixture is that in general its material is less desirable for the purpose than the earthenware or porcelain used for closets. On account of these deficiencies, for some ten years past, individual closets have been used in public schools in certain cities which have given the most attention to this branch of sanitation, and their use is being ex tended.