lly
important refuse liquid--viz., the waste water from washing and
stables, etc. As it is necessary to have drains for the purpose of
removing the waste water, it is more economical to allow this waste
water to carry away the excreta. In any case, you must have drains for
removing the fouled water. Down these drains it is evident that much
of the liquid excreta will be poured, and thus you must take
precautions to prevent the gases of decomposition which the drains are
liable to contain from passing into your houses.

There is a method which you might find useful on a small scale to
which I will now draw your attention, as it is applicable to detached
houses or small barracks--viz., the plan of applying the domestic
water to land through underground drains, or what is called subsoil
irrigation. This system affords peculiar facilities for disposing of
sewage matter without nuisance. There are many cases where open
irrigation in close contiguity to mansions or dwellings might be
exceedingly objectionable, and in such cases subsoil irrigation
supplies a means of dealing with a very difficult question. This
system was applied some years ago by Mr. Waring in Newport, in the
United States. It has recently been introduced into this country.

The system is briefly as follows: The water from the house is carried
through a water-tight drain to the ground where the irrigation is to
be applied. It is there passed through ordinary drain pipes, placed 1
ft. below the surface, with open joints, by means of which it
percolates into the soil. Land drains, 4 ft. deep, should be laid
intermediately between the subsoil drains to remove the water from the
soil. The difficulty of subsoil irrigation is to prevent deposit,
which chokes the drains; and if the foul domestic water is allowed to
trickle through the drains as it passes away from the house it soon
chokes the drains. It is, therefore, necessary to pass it in flushes
through the drains, and this can be best managed by running the water
from the house into one of Field's automatic flush tanks, which runs
off in a body when full.

When you have water closet and drainage, the great object to be
attained in house drainage is to prevent the sewer gas from passing
from the main sewer into the house drain. It was the custom to place a
flap at the junction of the house drain with the sewer; but this flap
is useless for preventing sewer gas from passing up the house drain.
The plan was th