E. E. M., South Orange, N. J., writes: "A friend of mine has been much troubled lately with a rumbling noise in the hot-water boiler connected with the plumbing in his house. In speaking of the matter to me I resolved to look into the connections and see if I could discover any reason for it.

Accordingly, I sketched out the run of the pipes, which sketch is herewith transmitted. I can find no explanation of the difficulty,and have resolved to trespass upon your space and see if you can assist me. The system is entirely clear from dirt. The water used is rain or artesian-well water."

[In the sketch, which we reproduce, B represents the boiler; T and P the supply pipe from tank; W, B, water-back; W, T, pipe to washtubs; S, pipe to sink; and B, R, pipe to bathroom. Rumbling noises in kitchen boilers, as complained of in this case, are not uncommon, and are due simply to the formation of steam brought about by a bright fire and a comparatively small demand for hot water from the boiler. The steam collects in the upper part of the boiler driving out the small quantity of water under the curved head through the small hole in the cold-water supply pipe P, a little below the point of entrance into the boiler. A very simple remedy for the noise would be to draw off some of the hot water from the boiler, allowing it to escape, say, into the kitchen sink, where it would, moreover, exercise a cleansing influence. The trouble, however, can scarcely be considered a serious one, indicating simply, as already stated, that there has been a falling off in the demand for hot water.]