er to life is hardly less than
that from the decomposition of faecal accumulations.

It is proposed now to set forth, in the simplest way and without much
discussion of principles (which may be studied elsewhere), the methods
and processes by which village households and communities may be
protected against the influences that come from an excess of
soil-moisture, from damp walls, and from imperfect removal or improper
disposal of organic filth.

We will assume that a village has a water supply sufficient to admit of
the use of water-closets in all houses, and to furnish a good flushing
for kitchen sinks, &c. A necessary complement of this work--indeed, it
should properly precede it--is the establishment of a system of sewers
by which all of this liquid outflow may be carried safely away. It would
be out of the question in a small or scattered community, especially
where roadways are unpaved, to establish any system which should
include in its working the removal of surface water. The moment we
undertake to make sewers of sufficient capacity to carry away the storm
water of large districts, then we enormously increase the scale and cost
of the work.

So far as the removal of house sewage alone is concerned, the work need
by no means be very costly. If a tolerable inclination can be given to
the line of sewers,--say a fall of one in two hundred,--a six-inch pipe
will have a capacity quite up to the requirements of a village of two
thousand inhabitants using one hundred gallons of water per day per
head. It will, however, be safe to use a pipe of this size only when it
is true in form and carefully laid, so that there shall be no retarding
of the flow at the joints from the intrusion of mortar, or any other
form of irregularity. Unless the joints are wiped quite smooth, the
roughness remaining will serve as a nucleus for the accumulation of
hair, shreds of cloth, and other matters which will hold silt and
grease, and form in time a serious obstruction. Nothing smaller than
six-inch pipe should be adopted for a street sewer. Unless the work is
to be most carefully done, for all but the branch lines, for a
population of five thousand, or less according to the fall of the sewer,
it will be safer to use eight-inch pipes. These pipes must be laid with
great accuracy as to grade and direction. All corners should be turned
with curves of large radius and regular sweep, and with an additional
fall to compensate for the increas