Fig. 408. Tilting Hopper.

Fig. 409. Air Vacuum Closet.

Air Vacuum Closet. Fig. 409 represents a water closet having a double trap, the space between the two being for a vacuum chamber. The vacuum is formed by the operation of the cistern which, in supplying the flush, withdraws air from the traps to take the place of the water. This is one of the first closets having a scientific form of basin and standing water therein, but the complication of the cistern and double trap are against it, and are now found to be superfluous in water closet construction.

Fig. 410. Wash Down Closet Washdown Closet.

This form of closet. Fig. 410, depends for its flushing upon the power of a stream or of streams and separate jets striking from above the surface of the water and its waste matters standing in the bowl. The quantity and surface of this water must be small, as otherwise the flushing stream, however powerful and copious, so applied proves inadequate to the task of ejecting the contents completely from the bowl and trap. The substances floating in the water are tossed and twirled about for some time before they come under the influence of the stream and jets calculated to submerge them. The water "piles up" in the bowl and a great waste is occasioned.

The force of the water is not judiciously applied. When the surface of the water standing in the bowl is large enough to perform its office of receiving the dejections with certainty and thoroughness their removal, if possible at all, is accomplished only with still greater wastefulness, and the roar of the cataract of water required forms, particularly when metered, no welcome music for the consumer. This type of closet was the most widely used of all before the advent into general use of the siphon jet closet, about 1885.

Fig. 411. Col. Waring's Original Siphon Closet, called the "Dececo."

Siphon Closet.

Fig. 411 represents a type of closet invented by Col. Waring, in which the wastes are discharged by siphoning action. A weir chamber is used below the trap to assist in charging the siphon. In the figure the weir chamber is shown below the floor, and is made in a separate piece from the rest of the closet. In later constructions the weir chamber is placed above the floor and made in a single compact piece with the rest of the closet. In order to charge the siphon the water is let into the basin through the supply pipe and the flushing rim until it overflows the outlet of the trap, and falls into the weir chamber below. The falling water drives out the air between the trap and weir, and if the quantity of water is sufficient it closes the inlet of the weir before it can escape through the outlet. This prevents air from entering the siphon. As soon as the siphon thus formed lowers the water in the bowl to the bottom of the dip of the trap air follows it and breaks the siphon. When the contents of the weir chamber fall below the inlet, and allow air again to enter the siphon. The bowl is refilled by the after wash. This was at one time a very popular form of water closet.

Washout Closet. Washout closets are those in which the basin is made to hold a certain quantity of standing water while the trap is placed below its level, usually entirely below the bowl. The outlet from the basin into the trap is above the level of the standing water. Hence these closets are sometimes called "side outlet" closets. In Fig. 412 is shown a washout closet made of a single piece of earthenware, and having the supply pipe opposite the outlet into the trap. This closet is also made with an earthenware body and an iron trap, and having the supply pipe in the rear. The flushing stream sweeps across the bottom of the bowl with considerable force and drives the waste before it into the trap. Whether or not the trap itself be emptied depends upon the length of time the flushing is continued after the bowl is cleared.

Fig. 412.

A defect in this form of closet is in the presence of the extended pipe surface between the basin and the trap, and of its upper corners near the cleanout opening, which partakes of the nature of a receiver. It would be better if this dry pipe or canal were not required. The smaller and more compact the surface of a water closet is the better. The trap is deep down out of sight and is somewhat inconvenient of access when it is necessary to empty it of its water, as is the case with water-closets of summer residences which are to remain unoccupied during the winter.

A second defect lies in the unscientific manner in which the flushing is accomplished, leading to a waste of water. Of that which rushes across the basin only a portion takes effect directly upon the waste matters, the rest spends its force upon the sides and back of the bowl to no advantage, and rebounding amuses itself in twirling the lighter substances about in small eddies for a time before it shoots them into the trap. In a perfect system of flushing no water should be wasted. Every drop should serve a useful purpose, and devote its entire energy to ejecting the wastes and the wastes only, solid and dissolved, but not the pure water, for as we have seen it is important for the most economical disposal of sewage, that it be diluted as little as possible.

A third defect is in the position of the trap, it being such that the water is either partially or wholly out of sight, so that it is impossible to know the condition of its contents, or even if it retains its water seal at all.

A fourth defect is in the spattering occasioned by the violence of the water flow, and a fifth in the excessive noisiness of the flushing.