Jay, of Riverside, Cal., writes:

"This city is provided with a system of pipe sewers tanging in size from 6-inch to 12-inch. Flush tanks on laterals Main sewer flushed from canal every week in addition. Rainwater excluded. Manholes with perforated covers at intervals As I understand it, there are the following well-defined methods of making house connections, it being understood that the house drain is extended through the roof in all cases: (1) Having no trap on the house drain, and ventilating the public sewer through it; (2) having a trap outside the building and a fresh-air inlet on the house side of the trap; (3) same as (2). but having, in addition, a ventilating pipe extending from a point between the trap and main sewer to a point above the roof outside the building.

" Will you kindly tell me which of these three methods would be considered preferable in the case of a system of sewers such as I have described ? The practice here heretofore has been No. 3, but there are not many buildings plumbed that way. The plumbers favor No. 1, while I might favor No. 2 under other circumstances; here, however, we have many detached closets and sinks in which any other method than No. 1 is hardly practicable. The climate is semi-tropic, and all houses are well ventilated by open doors and windows, and there are few large buildings."

[In our opinion, the choice lies between systems 1 and 2. We have usually preferred No. 2, simply because an ideal condition of the sewers of the average town cannot be permanently depended on.]