Q. In the arrangement of the main drain in my house there is a good current of air in at the ventilating-pipe in the rear and out at the top of the soil-pipe; but one plumber tells me that we ought to have another just such current to ventilate that portion of the drain between the bottom of the soil-pipe and the trap in front, and wants to put in a ventilating-pipe just outside of the front wall of the house. Another plumber says that it is often found in practice that these ventilators work the wrong way, and bring a foul smell into the windows; he says he does not think any ventilator is needed in front, anyway - that it is of no consequence to have a current of air passing through the front half of the drain, and that he would rather not have it at all if he could not run it up to the very top of the house. He adds that the ventilator in the rear is dangerous, and ought to go to the top of the house. Now, will you please inform me, first, whether it is necessary to admit air into the front half of the main drain; and second, if so, whether it would be safe to use the usual short ventilating-tube?

I desire also to say that my bath-tub wastes run into the traps of the water-closets, but I have never known of any smell in the tubs, and on trying the tissue-paper experiment I could not perceive any tendency to blow it off when a full pail of water was dashed into the closets. My water-closet traps are ventilated by a special pipe running above the roof; is this' why the paper was not blown off? And does the presence of this ventilating-pipe remove your objection to the arrangement?

One more thing. We are often very seriously annoyed by the behavior of the hot water at the stops over wash-stands. It comes at times in violent spurts, with a disagreeable noise, a tremor of the pipe, and such a splashing of the water as to drench your cuffs if your hand is under the hot water, and even to spatter all over your body. Sometimes the water runs smoothly for a minute before the spattering begins. Can it be remedied, and how?

A. A fresh-air inlet should be taken in at the front just inside the main trap. In our opinion it is important to have no dead ends in any part of the drainage-system - i. e., air should be permitted to circulate through every part of it. If rain-water does not pass the house-drain there is no object in extending it behind where the waste from the kitchen enters it, and this pipe should extend through the roof unless the soil-pipe passes near these fixtures. Then if the traps are ventilated from their highest points there will be no " dead end " between the drain and these fixtures. The presence of a vent-pipe from your water-closet trap, doubtless to a certain extent, prevented the sudden compression of air when the water was thrown in your water-closet. This does not remove the objection to running bath-waste into water-closet traps, because this waste is liable to become foul, and it is a sanitary axiom to place traps as near the fixtures they are intended to serve as possible.

The spasmodic flow from your hot-water faucets complained of is doubtless due to the fact that air-traps have been formed in the hot-water pipes, caused by depressions or sags in these pipes.

The Proper Way To Lay Stoneware Drains. Pipes made of stoneware were used extensively in ancient Rome as water-conduits, and were introduced in this country over twenty-five years ago for drains. After a few years of experimental use, the advantages of the mat erial over the old style of brick-drains were so obvious, and their cost so much less, that their manufacture and use has increased enormously. They have almost entirely superseded the use of brick. When properly made and put together no material is so good for drains, where buried in the ground outside of buildings. Their surfaces are indestructible for all ordinary service, only yielding to strong acids, such as may proceed from chemical laboratories or some kinds of manufacturing refuse. But the notion is very prevalent that any mason's tender who has begun to aspire to the use of the trowel can put them together well enough, and the result has been the wretched botching of by far the greater part of all the drains which have been laid in this material.

The natural result of this bad workmanship is the preference shown by the New York Board of Health, and other similar authorities, for iron pipes. The latter are generally put together with lead by plumbers, and these being also made in longer pieces than the stoneware pipes there is less chance of leakage at the joints. But iron is easily corroded, and it would be far better, provided good workmanship could be secured, to use the more imperishable material for all out-of-door drains, which after covering are necessarily difficult of access for repairs.

After many years of experimenting I have arrived at the conclusion that all stoneware pipes should be laid by none but first-class workmen, and even then the work should be tested by slight hydraulic pressure before it is buried deeply, so that defective joints can be readily seen and made good before filling up the trench.

The following specifications describe the method pursued in the sewerage of Princeton College and other places, which, if faithfully carried out, will insure satisfactory work: specifications for laying stoneware drains.