32. The duty of water closets is to thoroughly remove all filth that may be deposited in them. They must be free from all odors and must prevent the escape of odors from the soil pipe back into the dwelling. To meet these requirements, every closet must fulfil the following conditions:

1. The water used for cleansing must be applied in such a manner that it thoroughly washes all the interior surface of the bowl.

2. The current must have sufficient force to dctach all filth from the surface of the bow/.

3. The water must be of sufficient quantity to wash out all the filth and carry it beyond the trap and into the soil pipe.

4. When the flushing operation has ceased, the closet bowl and trap must be properly filled with fresh water, the foul water being entirely removed.

The thorough washing of the interior surface of the bowl is accomplished by introducing the water through a flushing: rim. This, when properly made, will direct the water in small streams over the whole internal surface. If any part of the surface be left unwashed, it will accumulate filth and emit bad odors.

The effectiveness of the current of water supplied by the flushing tank will depend greatly upon the shape given to the bowl, and upon the rapidity with which the water is projected into the bowl and trap.

33. A superior form of bowl is shown in Fig. 17. The bottom is of large area and is comparatively shallow. This . shape is called a washout closet. Water is supplied to the closet bowl through the 1 1/4-inch flush pipe F, and the perforated flushing rim R, the largest volume entering the bowl at the back. The depth of water remaining in the bowl should be 1 1/2 to 1 3/4 inches at the deepest point. If the basin is deeper, the fresh water may pass under the solid excreta and fail to remove it before the flush is exhausted; and if the basin is shallower, the excreta may adhere so strongly that it cannot be washed away without using more water than can be allowed.

The soil-pipe branch and trap are ventilated by the back-vent connection B, which joins a vent stack. The bowl may be ventilated by attaching a pipe to the local-vent connection L. This, however, is seldom done unless the pipe can be run inside or near a warm chimney. The lip S forming the seal of the trap A should dip not less than 1 1/2 inches nor more than 1 3/4 inches below the standing water in the trap. If the submergence of the lip be less than 1 1/2 inches, there is danger at times of its failing to properly seal the trap. The closet shown in Fig. 17 is called a. front-outlet washout water closet; it is also made with the outlet at the side, or at the back, as desired. The front outlet form is the best of the three. The closet is also constructed with the bowl separate from the trap, the bowl being of porcelain and the trap of iron. This permits the trap to be firmly calked into the cast-iron soil pipe, insuring a strong joint at that point.

Fig. 17.

.34. The closet shown in Fig. 18 is called a siphon-.jet closet. The contents of the bowl are sucked out by the siphon, which is formed by the two tubes C and D. Some of the water which enters the flushing rim A rushes down the tube G, forming a strong jet, which drives the water in C up into the space X and fills the tube D. As D is longer than C, the two act as a siphon until the water in the bowl falls below the lip B.

The closet outlet horn F is attached to the soil-pipe branch. The back-vent pipe H ventilates the closet branch and prevents the bowl from being siphoned by the discharge of other fixtures into the same soil pipe.

Washout closets make some noise while emptying, but the best of the siphon-jet variety are nearly noiseless. This class of water closets is considered to be the best upon the market at the present time. The vent hole H is generally omitted in siphon-jet closet construction now, because it has been found by experience that the porcelain horns soon break off or leak.

Fig. 18.

35. In another variety, called plunger closets, the emptying of the bowl is controlled by a valve, or plunger, which also acts as an overflow.

The drawback to this style of closet is that the chamber in which the plunger works is imperfectly cleaned and is liable to become foul. Unless the plunger is lifted well up when emptying the bowl, pieces of paper or matches, etc.

are likely to stick between the valve and its seat, and prevent the valve from closing. This allows the water to leak out of the bowl, leaving it dry if the closet is supplied by a self-closing valve or by a small tank overhead.

If the closet is supplied by a ball cock placed in the plunger chamber, a uniform water-line will be maintained in the bowl, and if the plunger valve should leak, a waste of water would be the result, which cannot well be detected. This variety of closet should not be used. In fact, it should be removed from all buildings where repairs or remodeling is being done.

36. In the hopper closet variety, the bowl is of conical form and is attached to a trap of any desired shape above the floor. Such closets should be provided with flushing rims in all cases, if used inside a building. If they are used without a flushing rim, they become very foul and emit a constant stench. Their use is not recommended.

The long hopper is the same as the short hopper except that it has no trap above the floor. It is suitable only for outdoor situations exposed to frost.

The hoppers and traps are made of solid porcelain, or of iron, either plain or enameled. The traps for long hopper closets are placed underground, clear of the frost, a straight vertical 4-inch pipe joining the trap to the hopper.

37. Water-closet seats are of many forms, but very few of them have a proper shape. Several State Boards of Health have settled upon the shape shown in Fig. 19 as the best form, and recommend its general use. They say: "The hole in the seat should be long from front to back, but narrow from side to side. It should never be made circular, as carpenters will do, unless otherwise instructed. The proper dimensions are 11 inches by 4 inches. The edges should be moderately beveled. This shape will make the act of relief much easier and tend greatly to prevent that painful disease-hemorrhoids."

Fig. 19.

Seats for hopper and washout closets are usually hinged to a back piece, which may be attached to the wall. The most improved patterns of closets are provided with lugs, to which the seat and cover may be hinged directly, and the seats are usually sold with the closets. All cabinet work or boxing of any kind should be avoided in setting up water closets.

No opportunity should be allowed for the lodgment of dirt or vermin. All the surroundings of a water closet should be kept strictly clean, and all arrangements of covers, pipes, traps, and safes should be made with that end in view.

Seats and covers should be provided with rubber blocks, or buffers of sufficient size and elasticity to prevent any damage by their falling down upon the porcelain bowl.

38. The soil-pipe connection, that is, the joint between the outlet of the water closet or trap and the soil pipe where it passes through the floor, is a matter of great importance. The common joint, which is made with putty, the flange being screwed to the floor, is rarely air or gas tight, although it may not leak water.

Porcelain closets are commonly attached by means of a brass floor-plate joint, as shown in Fig. 20. The soil pipe branch C, if of lead, is soldered to a brass flange D, which is screwed to the floor. A rubber, or, better still, a red-lead and hemp gasket A is put between the flanges, and the porcelain closet flange B is screwed down upon it by three or four screws or bolts, which should be of substantial size, and provided with washers, as at E.

Fig. 30.

Sometimes the lead pipe is flanged over on the floor, and the porcelain flange is set upon it with a bedding of putty. Such a joint will not remain gas-tight; it is worthless, and should not be allowed. Architects should specify the use of a brass floor-flange connection under each closet.