William McNair, Westbrook, Me., writes: " I send a drawing of a hot-water job which appears to be unlike anything described in " Plumbing and House-Drainage Problems." In Fig. 1 the return after coming 50 feet from the end of the cellar, has to rise above the second floor, and then drop to enter the boiler. The boiler supply and return have each an open pipe from the top of the boiler over the tank. The cellar circuit is carried along the timbers, with a fall of 6 inches to the return end, where a draw-off is put in. Another plan provides a connection of the return with the lower pipe to the boiler, shown by the dotted pipe A. with a shut-off to prevent drawing out the contents of the boiler when making repairs. Will either of these systems maintain a circulation in the cellar?"

[Our advice is not to attempt what you propose. It will not work and circulate in any form. The loop shown above the boiler will not help you. The up leg of the loop will lose as much heat, and theoretically a little more, than the down leg, and therefore will fully balance any gain due to the latter. It is a waste of time and material to construct circuits below the boiler. Run a circuit as shown in Fig. 2, and return below the floor, if you desire, and it will circulate if the pipe is free from air pockets.]