We come now to the class of water closets which is independent of valves, gates, plungers or mechanical seals or obstructions of any kind, and which accomplish both the removal of the wastes and the exclusion of sewer gas by the simple action of the flushing stream and by the water seal which it forms.

These closets have received the general name of "hopper closets." They do their work more effectively and by simpler means, and afford equal or better security against sewer gas than the complicated machines heretofore described, and must be placed far ahead of them. There is no point in plumbing in which sanitarians are more in accord than in this. But it must be borne in mind that there is the greatest difference in the different kinds of hoppers, and it is to the improved kinds that we refer in our comparison with other closets.

Hopper closets have usually been classified as "long" and "short" hoppers; i. e., those having the trap above and those having it below the floor level.

The trap should, however, never be placed below the floor except where it is necessary to avoid the effects of frost, and, as this is a condition which applies equally to all styles of closets, it marks no distinguishing characteristic, and can form no proper basis of classification for any special type. Abandoning, therefore, this old classification, and adopting for our basis the most important characteristic features of the closets, we make two general divisions, and further detailed subdivisions.

Fig. 406. Dry Hopper.

Fig. 406. Dry Hopper.

The general divisions are (1) Those which have no standing water in the bowl to receive and deodorize the waste matters and prevent their striking and adhering to dry surfaces. These may be called "dry" hoppers. The water stands only in the trap. (2) Those whose bowls are formed to retain a permanent body of water in the bowl so that no part of the interior can be soiled by waste matters striking them. These we may call "improved" hoppers.

DRY Hoppers. Fig. 406 represents a wash-down water closet of this class having the trap above the floor, and when the water seal is small it is usually called a "short" hopper.

Fig. 407 represents the same kind of a closet with the trap below the floor, and is then called the "long" hopper. It is intended to be used in cold places where the water in the trap can only be protected from frost by burying the trap in the ground. It is sometimes said that the wastes are more easily ejected from the trap of the long hopper on account of the greater weight and momentum of the falling water. But what little may be gained in this direction is far more than offset by the disadvantage of having an increased dry surface to be fouled above the trap, and as there is no difficulty in ejecting the contents of a trap above the floor when the flushing stream is properly constructed, this form of hopper is most strongly to be condemned except where frost renders it a necessity. Even where great cold is to be guarded against, however, it is better to properly pack the trap above the floor where this can be done. The trap of the long hopper is so low down as to be practically out of sight, and when unsealed by momentum or otherwise the accident may easily escape discovery.

The seal of the dry hoppers is much too shallow, a consideration of the first importance in water closets, as will be hereafter shown.

Fig. 407. Long Hopper.

Fig. 407. Long Hopper.

It will be seen from the drawings that the surface of the water in the trap of these closets is entirely insufficient in area to receive the wastes, which fall upon the dry sides of the bowl, and require constant attention and disagreeable labor to remove them. On account of this defect, dry hoppers are sold at a low price, and they are bought to save in first cost, under a mistaken idea of economy. They should never be used in the better class of houses because the trouble necessary to keep them clean will not be endured; nor in the poorer classes because the trouble will not be taken, and the closet soon becomes a nuisance in the house. Or if, by exception, cleanliness in this direction be insisted on, the extra labor and consumption of water soon offsets the saving in first cost.

It is easy to see that the water required for cleaning the dry hopper is very much greater than for the improved kind, whether the scouring be done by the strength of the flush or by manual labor, for, as is well known, soil adheres with the greatest tenacity to a dry surface. In view of this fact, dry hoppers have to be constructed with a copious and powerful flush, and there is a strong temptation for the user, and especially for servants having them in charge, to try to remove the tenacious substances by prolonged flushing in order to avoid a disagreeable manual labor. This practice occasions a waste of water far greater than most people imagine.

An effort has been made to overcome this objection by using a valve or cistern constructed to give a small prelim-nary wash before using. But this complicates the construction and adds to the water consumption, adding enough to the first cost to pay for a hopper of proper construction, and to the subsequent operating expense, to pay interest on the very best fixtures. The preliminary wash, moreover, is really quite insufficient for the purpose.

Improved hoppers may be subdivided into seven classes, as follows (a) tilting basin, (b) air-vacuum, (c) wash down, (d) trap jet, (e) siphon, (f) wash out, and (g) self-sealing closets.

Fig. 408 represents a water closet of this class. Its peculiarity consists in having a double bowl, like the Jennings tilting wash basin. The outer basin is connected with an ordinary S trap and is stationary. The inner basin is pivoted to tilt after use and empty its contents into the stationary basin, whence they are supposed to pass out into the soil pipe. The tilting is done by hand. This is a very bad and clumsy arrangement. The stationary bowl corresponds with the receiver of the pan closet and partakes of its defects. The inner bowl conceals the trap, which should be visible, adds greatly to the complexity and cost of the closet without having any advantage, and necessitates a disagreeable manual labor in tilting.