26. Houghton’s Trap.
One of the best modern traps is that introduced by Houghton (Fig. 26), in which the outlet a at the bottom of the gully can be pointed in any direction, and the inlet b to the basin c of the gully, forming a movable half, can be turned round to accommodate the entering waste pipe b; d is the open grating which covers the gully.
Drains.—Tho drain itself is got at by opening down to it in the front area. It may be found to be an old brick-drain, in which case it ought to be taken out. Brick drains are pervious, they allow the escape of foul air, and with contaminated air rats also get in the house. Wherever rats can get, foul air can go; and rats coming in through these holes may carry with them the poison of disease, such as typhoid fever. Rats generally go to the larder, and carry with them often the poison of such diseases, which are very largely spread by their poisons being taken in this way by rats into the milk and other foods, and also into the water in the cisterns.
Whether a brick drain or a pipe drain, it should be trapped before it is connected with the main sewer or cesspool. This trap, in the case of a brick drain called a “dipstone” trap, is a brick pit with a stone across it from one side to another, and dipped into the water which remains in the pit. The object of this stone is to prevent foul air coming into the house. As a matter of fact, the pit holds a large collection of foul matter and becomes a small cesspool, indeed, there is no difference between them.
A drain may be made of glazed stoneware pipes, which may be joined together in one of several ways. They may be laid “dry,” i.e. without any jointing material between the ends, in which case they are, of course, not water-tight; or they may have clay in the joints, in which case you cannot fill them with water—that is to say, they will not hold water under pressure. (If you fill them with water, by plugging at the lower end, the water will come out at the joints.) Or they may be laid with the pipes the wrong way. When the joints are made with clay they will very soon become leaky; and when that happens, the water oozes through the joints, filth collects in the trap, and it gradually plugs up the whole drain from one end to the other. This may go on for years without being found out, and so cause the ground under the house to gradually become a large cesspool. This is an extreme case. Or they may be jointed with cement, and there are some other ways. They may be perfectly well jointed with cement, so as to be water-tight. The drains, then, should answer to this test, i.e. you should be able to plug them at the lower end, and fill them with water. They should not be under the house, if possible. In London we cannot help it as a rule. If under the house, the straighter the course of the drain the better. Do not let it wind about in order to get away from different rooms. The best thing is to have a straight course through and to see that it is water-tight. It should hold water like a teacup. The drain must not be directly connected with the main sewer or merely separated by a siphon trap; but there should be an air inlet into the drain between the siphon trap and the house. This opening may be of different kinds. The best kind is that of a manhole for access to the drain and trap (so that the trap can be examined and cleared out at any time); the air inlet should be a grating either over the manhole or in the nearest wall opening into a pipe leading into the manhole.
People who are afraid of foul air coming out of these inlets put on a valve with mica flaps, so that the air can blow in, but foul air cannot go out. But, if there are no D traps under the water-closets and sinks, if the pipes are straight and sufficiently large ventilators are used, if the ventilating pipes go up above the roof and are not protected from the action of the wind, you will never find foul air coming out at the air inlet though you will find that fresh air is drawn in. There can be no accumulation of foul air, and the air that may be occasionally forced out is the last fresh air that has entered. Should you, however, find foul air coming out you will know that there is something wrong with the drain, that the drain or siphon is plugged, so that this air inlet becomes most valuable in pointing out when anything is going wrong.
Brick drains, says Eassie, are variously shaped. The worst sections are those upon which two upright sides of brick have been built upon flat stones, so as to form a bottom, and then covered over with other flat stones, because the bricks can never joint tightly with the stone, and there is always a leakage going on into the surrounding subsoil. One great objection to brick drains is due to the fact that they cannot be constructed sufficiently small to meet the requirements of a house, and consequently are seldom found less than 9 inches in diameter, which is far too large a sectional area to properly drain a house.
However compactly and well-burnt the clay has been made into bricks, a brick drain has only a certain life, so to speak, before its decadence begins with the usual attendant danger. Its lifetime is longer or shorter according to the subsoil in which it is placed, the material used as mortar, the gradient at which it is laid, the sewage which it removes, and the quantity of water, and especially of heated water, which passes through it, but the consensus of opinion in their disfavour for use in the interior of a house is overwhelming, and a universal preference is accorded to drains formed of earthenware pipes. A second objection to brick drains, however well they may have been built, is their want of smoothness, especially at the bottom, whereby the effete matters are not carried easily away; and this want of smoothness is aggravated by the roughness due to the unequal perishing of the bricks.
One of the first proofs of the perishing of a brick drain, making it past redemption, is the appearance of rats. Rats will go always to that place which affords them most food; and it is the brick barrel drain which receives the washings from meat plates, and the grease from the scullery pots, which rats most commonly frequent. They will leave a drain, and nest themselves in the thatched roof of a farmhouse, and they will form whole villages under the floors of a town house. Rats generally find their way into houses by means of holes which have been formed in brick drains by the falling down of perished bricks from the arch, or owing to their having contrived to make a passage through the brick drain above the usual wetted perimeter. These rats, in the case of country houses, may come from the stables, the barns, or the brooks; but in town houses they chiefly emanate from the sewer. No matter whence originally derived, they soon become habituated to a house and its dainty scraps, and having once engineered their way thither, are seldom effectually dislodged, especially in country residences. As fast as a hole is discovered and stopped up, another is made by these persistent vermin, until the foul air evolved from the house drain becomes so distressful, and the rats so multiply, that some further steps are necessary in dealing with them. Where the evil has not yet grown formidable, traps are made use of, or poison; but this last is a dangerous resource, as the rats are apt to die underground and emit during decomposition, which lasts for months, the most horrible smells.
It may be added that rats are remarkably clean animals, and will never allow their fur to come in contact with anything that cannot easily be immediately cleaned from it; hence, very often a dairy, larder, or granary is surrounded by a trench outside the brick walling to a certain depth, by broken glass and gravel, well grouted with tar. Never rely upon a siphon trap in the drain, as a means of keeping out these voracious and fast-breeding animals. They will eat even through lead pipes ⅛ inch in thickness.