Soil-pipes entering flues.

Where the pipes are proved tight, the peppermint may show leaks around the fixtures. Most water-closets, for instance, which have the trap formed in the porcelain, including the siphon and washout patterns, as well as the all-porcelain short hopper and wash-down closets, make the connection between the outlet of the porcelain closet and the lead branch of the soil-pipe by means of a projection of the porcelain, which fits loosely into the lead pipe, the joint being filled with putty. In practice, the end of the lead pipe is brought up through a hole in the floor and "flanged out" around the opening; and, after a mass of putty has been spread on the floor about the opening, the closet is set in place, the projection entering the mouth of the lead pipe, while the spreading porcelain foot covers the putty on the floor. The bolts which hold the closet to the floor are then put in and tightened until the putty is squeezed out to the edge of the foot, when it is trimmed off, and the setting is complete. In most cases this makes, at first, an air-tight setting; but if the closet is repeatedly taken up, to prevent it from freezing in winter, or if the floor should shrink materially, or the closet become displaced, a crevice may be opened in the putty, through which sewer-gas will pass directly from the soil-pipe. A leak of this kind is immediately exposed by the peppermint test, and is remedied without difficulty by unscrewing the bolts, and the coupling which connects the closet with the flush-pipe from the cistern, detaching the local vent, if there is any, by the slip-joint which is always used in connecting it, and taking up the closet, putting down fresh putty, or grafting-wax, which is preferable to putty for the purpose, and resetting and reconnecting the closet.

Leaks around fixtures.

As a leak of this kind may exist for a long time before it is detected, to the injury of the health of the inhabitants of the house, closets with metal traps, which can be soldered permanently to the branch of the soil-pipe, are preferred by many architects. In this case the detachable joint, by which the closet is removed and reset, when necessary, is between the porcelain bowl of the closet and the trap. If this joint should not be perfectly tight, which is frequently the case, water will leak through it from the closet-bowl on the floor; but, as the leak is on the house side of the water-seal of the trap, no sewer-gas can come through it so long as the water remains in the trap, and no harm will be done beyond the wetting of the floor. With certain forms of metallic-connection closets, however, a leak between the bowl and the metal trap may drain the water out of the trap, destroying the seal, and opening a passage for floods of sewer-gas; so that each form has certain advantages as well as disadvantages. Some expensive all-porcelain closets, instead of requiring putty for making the joint with the branch of the soil-pipe, have a provision for packing the connection with copper or lead gaskets; but there is room for further improvement in this direction.

After the persevering householder has investigated the cesspool, the foot vent, and the chimneys, applied the peppermint test, and repaired the leaks in pipes and fixtures, he may still be troubled by unpleasant smells, the. cause of which his search has failed to disclose. These will generally be found on closer inspection to proceed from the overflow openings of washbasins, baths, or pantry sinks. If these fixtures have stand-pipe overflows, the trouble may easily be remedied by taking out the stand-pipes and cleaning them, with the recesses or tubes containing them, with a sponge or rag tied to a stick or stout wire, using ammonia or soda, if necessary, to dissolve and remove grease. If the fixtures, on the contrary, are of the old-fashioned type, the overflow may be inaccessible to a sponge, and it is in overflows of this sort that smells are most likely to occur, as the overflow-pipe in such cases is comparatively long, and, when lined with a mixture of old soap, hair, epithelium cells, and similar materials, is capable of giving off an aroma of astonishing power. Bath-tubs, which have a long and large overflow, seldom washed, except by the soapy scum of a hot bath, often become surprisingly offensive, particularly in hot weather; and wash-basins, especially in nursery bath-rooms, where milk occasionally gets into the overflow, may be hardly less so.

Overflows.

When a smell of this sort is traced to the grated opening of an inaccessible overflow which cannot be sponged out, a slow, but tolerably efficient cleansing can be given it by filling the fixture to overflowing with clean water, and allowing washing soda or ammonia to mix with the current as it passes through the strainer. In the case of nursery wash-basins or sinks in old houses, where the overflows are of lead, even this treatment may not be sufficient, as decomposing milk seems to saturate a lead pipe beyond recovery; and, under such circumstances, it may be necessary to cut out the lead overflow-pipe and substitute a fresh one, or put in a modern fixture with a stand-pipe, or an overflow formed in the porcelain.

Defects in supply-pipes commonly show themselves by leaks, which may assume all proportions. The worst leaks are, perhaps, those due to the splitting of unannealed brass pipes, which may deluge a house in a few moments; but even unannealed brass pipe does not always split, while respectable plumbers generally use annealed pipe, so that accidents from this cause are rare. Iron pipes give much more annoyance by filling up with rust. With some waters a badly coated or defective iron pipe, even if enamelled or galvanized, may choke completely with rust in a month, while the best galvanized pipes sometimes serve perfectly for many years; but there is always a chance of trouble with iron supply-pipes of any kind. Where they are exposed to freezing, also, iron pipes should be avoided, as the freezing of such a pipe generally splits it for nearly its whole length, causing a destructive leak when it thaws again, while a lead pipe, in freezing, bulges locally, opening at most a small hole, which does not give passage to much water on thawing, and can be closed by a drop of solder.