The most important and useful plumbing fixture in a house is the water closet.

Water closets should be in all houses that make any pretentions towards convenience. That they are a vast improvement over the old-fashioned, offensive privy vault in the back yard, everybody will acknowledge. But it is equally true that, unless of a good pattern, properly fitted up, properly used, carefully watched and frequently cleansed, they may become not only the sources of foul smell but also the cause of disease.

Leaving aside the question of the pollution of the soil and of well waters, of which the privy vault must sooner or later be the cause, it is in itself a nuisance and an abomination. In cold weather and during rain storms persons are liable not to use it when they ought to, and trouble of the digestive organs is sure to follow, as every physician knows. This is especially the case with females and with delicate children. Sick persons and invalids may suffer severely from exposure to the weather. Add to this the often unbearable stench emanating in hot weather from such vaults, and it will be readily seen how superior in point of convenience, health and cleanliness an indoor water closet is.

There are other improved devices for receiving faecal matters, such as earth closets, ash closets, tubs or pails, which are far preferable to privies, and should be recommended wherever water is scarce; but these do not properly belong to my subject, which refers only to the "water carriage" system.

There is an endless list of water closets, and each year increases the number of newly invented and patented articles. It is, of course, impossible, nor is it even desirable, that my paper should give a complete description of all of them. I shall limit myself to describing the chief features of the various types of closets, mentioning a few examples of each type.

After reviewing the different patterns of water closets in use we shall speak of the general arrangement of the water closet apartment with respect to light and air.

The essential points to be considered in examining water closets are: the shape of the bowl or vessel receiving faecal matter; the apparatus for discharging the contents of the bowl; the manner of trapping the water closet; the manner of flushing the bowl and the trap; and the ventilation of the water closet.

The less surface a water closet has exposed to fouling, the cleaner and better will it be. All foul discharges should pass into water as quickly as possible. Thus the fouling of the sides of the vessel will be efficiently prevented and the water will have a tendency to deodorize the excrements. All water closets holding a large body of water in the bowl (valve and plunger closets, wash-out closets and latrines) have this advantage. In other closets, where the body of water is in the trap (hoppers), this latter should be as near as possible to the bowl (short hoppers are preferable on this account), and the rear side of the vessel should be designed nearly vertical and straight to prevent foul matter from soiling the bowl before passing into water.

A further requirement is durability and simplicity of the working apparatus The less moving parts a water closet has the better will it be. We must have regard to the rough usage to which such fixtures are sometimes subjected, especially in public places. Complicated or delicate mechanisms frequently get out of order, or fail to work properly under children's or servants' hands. Nobody can deny that, so far as this point is concerned, hopper and wash-out closets are vastly superior to pan, valve and plunger closets.

Each water closet should be separated from the drain or soil pipe by an efficient trap, placed either above or below the floor, and protected, whenever necessary, against siphonage. I consider one good trap as entirely sufficient, and do not have much faith in the additional water seal afforded by the water in the pan of a pan closet, or the water in the bowl of a valve or plunger closet. The copper pan quickly corrodes through the action of sewer gas in the container, and the flap valve gets leaky in time, while with plunger closets flushed from a cistern the bowl may lose its water if the outlet is imperfectly closed, as may happen, when paper remains clinging to the seat of the plunger. Wash-out closets are sometimes provided with a double trap, which is an obstacle to a proper flushing, and which may accumulate filth in the hidden and mostly unventilated space between both traps. I consider a double trap as unnecessary here as on the main house drain. Washout closets, the basin of which is shaped so as to form an efficient trap, and short hopper closets with trap above the floor, should not have a second trap (of either iron or lead) underneath.

The contents of a water closet trap should be thoroughly changed at each use of the closet, which can be accomplished by an efficient and liberal flush. This leads us to consider the supply of water to such apparatus.

A water closet should have a copious supply of water completely to wash at each use the bowl and trap as well as all surfaces coming in contact with foul matter. I do not, however, wish to be understood as favoring reckless waste, for it is well known that allowing the water to run continuously through a water closet cannot be regarded as flushing. Two or three gallons properly applied at each use will cleanse a water closet more thoroughly than an uninterrupted trickling flow of water. In order to be efficient the flushing water should come down "in a sudden dash" To make the flush effective the supply pipe from cistern to bowl should be of large diameter, never less than one inch, and increasing up to 1 1/2 inches as the head (or height of bottom of cistern over the bowl) diminishes. The force of the flush largely depends upon the shape of the bowl and upon the head of water available in each With closet bowls, circular in shape, a flush introduced in the direction of the tangent will whirl around its circumference, losing its force without effecting much cleansing. An oval bowl provided with a fan flush is a vast improvement. The best bowls are those provided around the upper edge with a proper "flushing rim," into which the water from the supply pipe enters simultaneously at all sides, and is directed to rush vertically downward, thoroughly washing the sides of the closet and retaining sufficient force to expel the foul contents of the water closet trap.