IN public buildings and for general purposes, where the closets would be in constant use - to prevent evaporation of the water-seal of the trap - I should be content to fix self-cleansing wash-down closets, though I should want the traps of lead when they were fixed upstairs, for connection to the soil-pipes, as shown in fig. 138, by wiped soldered joints.

2. For private closets, and where the closets would not be used for weeks together, I should greatly prefer valve-closets, of the best description; and I should consider that I had gained the following advantages by adopting this class of closet, viz.:-

(1) A large exposed surface of water in the closet, greater in area than the seat-hole, to prevent the faeces falling upon any part of the basin, and adhering to it.

(2) A large body of water to receive faecal matters, (a) to dilute the liquid portion, and (b) to convey the solids away through the closet-trap and soil-pipe in a sort of water envelope.

(3) A great depth of water, for a costive motion to (a) be well and completely submerged under water; and (b) to prevent fumes rising from it into the closet-room.

(4) The thorough emptying of the basin, together with the flush of water coming into it, simultaneously, to free the closet from every vestige of matter passed into it.

(5) Supposing the closet to be out of use long enough for the water to evaporate out of the basin, there would still be the basin-valve to exclude the soil-pipe air; or if the basinvalve were defective, the water-seal of the trap would remain as an air-barrier to the soil-pipe. I have made many trials, and have found that after several months, when the water has evaporated out of the basin, the trap has still retained a seal, though after a few months the seal gets much reduced. A trap ventilated on the crown of its outgo would not maintain its seal anything like so long as a trap ventilated some little distance away, as shown in fig. 112 and fig. 112a. (Chap. XXIII., Art. 13.)

Fig. 133.

Fig. 134. - Section showing two Valve-Closets, with Traps, Soil-Pipes, and Trap-Ventilation.1

1 Vents from valve-boxes carried out to the open air.

(6) The trap being independent of the closet, a removal of the latter for repairs, or in case of breakage, leaves the trap still standing, to keep the soil-pipe air out of the house.

(7) The trap being of lead, its connection with the soil-pipe by a wiped soldered joint is permanent and reliable - a most important consideration. (Chap. XXXI., Art. 1.)

3. In using a valve-closet strangers often pull up the handle such a little way that there is no room for the paper to pass out of the basin, the consequence is that pieces of paper are often caught between the outlet of the basin and the basin-valve, and then when the next visitor comes to the closet he finds no water in it, and condemns the closet, instead of condemning the person who so badly treated it. [A printed notice put up in a conspicuous place in the closet-room, telling strangers how to pull up the closet-handle, generally corrects such an error.]

4. There is another drawback to valve-closets. Where there are no slop-sinks, a servant wishing to empty a pailful of slops into the closet finds herself for the moment in the want of three hands, one to pull up the closet-handle, whilst with the other two she empties the pail. I have provided for this in my patent "Optimus" closet with downright overflow, etc., fig. 133. A pailful of water can be emptied into the closet, and then when the handle is pulled, a flush of water will pass into it, to cleanse the closet and charge the basin with clean water.

5. Many valve-closets are made with most defective overflow arrangements. An overflow-pipe is often carried from the basin into the valve-box without a water-seal, or with a seal so small that for the purpose of preventing a passage of air from the valve-box into the closet apartment it is practically of no value, and is worse than useless. The evil of an inefficient seal (fig. 135) is further aggravated by the fact that very often in such cases the overflow-trap is only charged when a pailful of slops is emptied into the closet.

6. In fig. 134 I show two of my patent " Optimus " closets, fixed with lead " Anti-D-traps " under same, and branching into a stack of 31/2 in. 8 lbs. lead soil-pipe, with 2 in. lead anti-syphoning pipe, all complete, and 2 in. lead puff-pipes or vents to valve-boxes, the ends of which are left open to the atmosphere.

7. In fixing traps for valve-closets be careful to leave a wide margin for the seat-rail at the back, for clothes. Where it can be allowed, 16 in. or 17 in. from the centre of the dip of trap to the face of the plastered wall at the back of the closet answers very well. In fixing traps care must always be taken to so fix them that they shall have their full seal. Where there are no safes the mouth of the dip should be rounded over and soldered to a lead flange, or be very carefully tafted back and rebated into the floor.

8. Where the closets are open to view and the floors are of marble or tiles, an overflow-pipe fixed to the floor and carried through the wall is all that is necessary to prevent a ceiling from being washed down, in case of a breakdown of the service-pipe or supply-valve, from frost or any other cause. In such cases it is well to give the floor a fall all ways towards the overflow.

9. Where the closets are inclosed it is better to fix a lead safe (or tray) under them, with a stand-up 4 in. high on each side, and large enough to catch any water which may flow over from the closet-basin at any and all points. It is the custom with some plumbers to dog's-ear the corners, but the corners are better either bossed or soldered; for in case any filth washed over the closet at any time the matter might find its way between the corner lappings, and remain there.

Fig. 135.- Overflow-Trap, Inefficient Seal.

The safe should be soldered to the closet trap, as shown in fig. 16, Chap. VIII.

The mouth of the overflow-pipe can be opened out a little with a turn-pin, and soldered to the safe, as shown at a, fig. 136. But in all cases the end of the pipe must be made to discharge into the open air.

It is usual to fix a brass or copper-hinged flap on the end of the overflow-pipe, D, fig. 136, for the double purpose of excluding draught and preventing birds building in the pipe. But where it is desirable to utilize such a pipe for the purpose of admitting air into the closet-room, and where there would be no risk from such a treatment - from pipe freezing, etc. - a copper bird-guard can be fixed on the end of the pipe (instead of the flap) for keeping out birds. But where the end of an overflow-pipe faces the north or north-east, and the mouth of the pipe, a, inside the closet-room stands also inside the closet inclosure, there would be danger of the service-pipe freezing, and also of the supply-valve, as well as the water in the closet-basin.

Fig. 136. - Safe and its Overflow-Pipe.