is one below the safe, but it is occasionally carried straight into the soil-pipe, with or without a siphon bend on it. When carried into the D-trap, it is usually made to enter below the surface of the foul water therein contained, but I have seen it carried straight into the top of the trap, so forming a passage for foul air into the house. It ought not to be connected with any part of the water-closet apparatus, trap or soil-pipe, but ought to be carried straight through the wall to end in the open air, being merely provided with a small brass flapper to keep draughts out. The waste or overflow pipes of cisterns are frequently carried into the D-traps of closets, in which case foul matters get washed into the inside of these pipes, and foul air from them contaminates the water in the cisterns. This is even a greater evil than the last, and the waste-pipes of all cisterns, but more especially of those used for the supply of drinking water, should, as stated in a previous chapter, be made to end in the open air.

We come now to valve closets, the numerous varieties of which are modifications of the original Bramah's valve closet. In this the aperture at the lowest part of the basin is closed by a water-tight valve, which can be moved in a small valve box, placed immediately below the basin, by means of the pull-up apparatus-the valve box itself being connected below with the trap. Thus, the necessity for the large iron container, so objectionable a part of the pan-closet, is done away with, and its place taken by a small box, in which the valve moves. As, however, the valve is water-tight, provision is made for the overflow of

water from the basin, in case the latter should be filled too full, either by slops being thrown into it, or by the water continually running from the supply-pipe in consequence of a leaky valve. The overflow pipe starts from one side of the basin in which holes leading into it are perforated. It is then as a rule, carried downwards into the valve box, having a small siphon bend on it before entering. The water from the supply-pipe, as it enters, is made to flow round the basin by an inner plate, generally made of metal, called the "spreader," or still better, in the improved form of valve-closet, by means of a flushing rim. Thus, some of the water at each use of the closet passes through the holes leading into the overflow pipe; the object of this being to keep the siphon on that pipe charged with water, as it is clear that if this siphon is not charged, the overflow pipe ventilates the valve box, that is to say the space between the valve and the surface of the water in the trap below, into the basin of the closet. Now, as a rule, the siphon trap on the overflow pipe does not remain charged with water, and even if it does, is of little use for the following reasons;-when by the pulling up of the handle the valve is made to move suddenly in the valve box, air from the latter is forced out through the water in the siphon bend of the overflow pipe, as any one can see, who will take the trouble to place a piece of moist tissue paper over the holes in the side of the basin leading into that pipe, and then work the handle of the closet; thus foul air from the valve box is driven into the basin, even when the siphon on the overflow pipe is charged. Furthermore, as

the mass of water in the basin rushes down through the valve box into the trap it carries the air along with it, and when the valve is closed runs out of the valve box, drawing air through the overflow pipe, and displacing the water in the siphon, which is in many cases left quite uncharged. Various remedies have been proposed for this. In Bolding's "Simplex" valve closet a small pipe is carried from FIG. 36.

the water-supply pipe into the overflow just above the siphon, with a view of supplying water direct to the siphon each time the closet is used. In Jennings's valve closet the overflow is trapped by means of a patent indiarubber ball trap, which is something like a Bower trap upside down. It is constructed so that the overflow water can displace the ball from the end of the water-pipe and flow away around it, but any pressure of air from the valve box would only cause the ball to fit more closely against

the end of the overflow pipe. In the valve closet made by Dent and Hellyer, the overflow pipe is made much larger than usual, and the siphon deeper, so that it holds a larger quantity of water, and at the same time a ventilating pipe is inserted into the valve box and should be continued through the wall to the outer air. By this means no accumulation of foul air in the valve box can take place, and air that is drawn into it, while the water is passany ing through it, comes in through the ventilating pipe instead of through the overflow. It is quite right to ventilate the valve box, but the best way to deal with the overflow pipe is to disconnect it altogether from the valve box, and either carry it through the wall, placing a brass flap on the end of it, or let it end over the waste pipe of the safe. Indeed, it is hardly necessary to have an overflow pipe at all, as if the basin does get full, all that will happen is that the water will flow over the top of it into the safe and run away. The advantage of this plan is that the existence of a leaky valve is found out immediately, and the disadvantage is that it is liable to wet the under part of the seat and apparatus below it. Lead D-traps are generally placed under these closets, but this should never be allowed. Siphon or "Anti-D" traps should always be used, for the reasons already mentioned. Some valve closets are made with a galvanised iron siphon trap that is to be placed wholly or partially above the floor, and is provided with a screw cap that can be taken off for the purpose of cleaning; such closets are made by Messrs. Tylor and Sons, and Messrs. Jennings. The latter also make closets, which

may be called "plug" closets, the best known variety having the basin and siphon trap all in one piece of china. The plug closes the entrance from the basin into the siphon below, and is connected by a rod with the handle, which is vertically over it. By means of an india-rubber flange the plug is made to fit water-tight into the entrance of the siphon, and a body of water is kept in the basin above it, up to the level of the overflow, which is either made through the plug and the rod joining it with the handle or by a separate trapped channel alongside of it. A plug is also made containing the patent ball trap mentioned above. It will be seen that in these closets, no valve box is necessary, and there is only a small air-space between the water in the trap and that in the basin. These closets are also made without any trap at all, in which case the overflow of the basin is carried, by a pipe, straight through the wall. Such trapless closets are occasionally useful on the ground floor, where the soil pipe can be carried straight through the wall and disconnected from the sewer by a ventilating trap outside; but when used in any other way, trapless closets are very liable to become a nuisance.

We must now consider more in detail the arrangements for the supply of water to the basin. The simplest form of water-waste-preventer has already been mentioned, but it must be remembered that the commonest plan for supplying closets with water, is to place a spindle valve on a valve box in the bottom of a cistern somewhere above them, so as to guard the entrance into the pipe leading to the basin of the closet, and to work this valve by means