Very few instances occur where traps are placed as close to the fixtures
they serve as they might be, and yet a very short length of untrapped
pipe, when fouled, will sometimes smell dreadfully. A set bowl with trap
two feet away may become in time a great nuisance if not properly used. A
case in point where the fixture was used both as a bowl and a urinal was
in a few months exceedingly offensive--a fact largely (though not wholly)
due to its double service.

I have never met two sanitarians who agreed upon the same water-closets,
bowls, faucets, traps, etc.

Of course, the soil pipe will be carried, of full size, through the roof,
and sufficiently high to clear all windows.

Avoid multiplicity of fixtures or pipes; cut off all fixtures not used at
least twice a week, lest their traps dry out; have all plumbing as simple
as possible, and try and get it all located so that outside air can be got
directly into all closets and bath-rooms. As far as possible, set your
fixtures in glass rather than tiles or wood. Carry the lower end of the
main drain at least five feet beyond the cellar walls of the building, of
cast iron.

Let us now look at the outside work. The main drain (carrying everything
except the kitchen and pantry sinks) goes through a ventilated running
trap. An indirect fresh air inlet is provided on the house side of the
trap (example), to prevent annoyance from puffing or pumping, or, better
still, a pipe corresponding to the soil pipe is carried up on the outside
of the house.

The running trap ventilator should be of the same diameter as the main