HOUSE DRAINAGE, SHOWING THE PLUMBING OF A HOUSE. (H.
BRAMLEY.)]

_Fall._--The fall or inclination of the house drain depends on its
size. Every house drain must be laid so that it should have a certain
inclination toward the house sewer, so as to increase the velocity of
flow in it and make it self-flushing and self-cleansing. The rate of
fall should be as follows:

For 4-inch pipe 1 in 40 feet
" 5 " " 1 " 50 "
" 6 " " 1 " 60 "

_Position._--The house drain lies in a horizontal position in the
cellar, and should, if possible, be exposed to view. It should be hung
on the cellar wall or ceiling, unless this is impracticable, as when
fixtures in the cellar discharge into it; in this case, it must be
laid in a trench cut in a uniform grade, walled upon the sides with
bricks laid in cement, and provided with movable covers and with a
hydraulic-cement base four inches thick, on which the pipe is to rest.
The house drain must be laid in straight lines, if possible; all
changes in direction must be made with curved pipes, the curves to be
of a large radius.

_Connections._--The house drain must properly connect with the house
sewer at a point about two feet outside of the outer front vault or
area wall of the building. An arched or other proper opening in the
wall must be provided for the drain to prevent damage by settling.

All joints of the pipe must be gas-tight, lead-calked joints, as
stated before. The junction of the vertical soil, waste, and
rain-leader pipes must not be made by right-angle joints, but by a
curved elbow fitting of a large radius, or by "Y" branches and 45 deg.
bends.

When the house drain does not rest on the floor, but is hung on the
wall or ceiling of the cellar, the connection of the vertical soil and
waste pipes must have suitable supports, the best support being a
brick pier laid nine inches in cement and securely fastened to the
wall.

Near all bends, traps, and connections of other pipes with the house
drain suitable hand-holes should be provided, these hand-holes to be
tightly covered by brass screw ferrules, screwed in, and fitted with
red lead.

"No steam exhaust, boiler blow-off, or drip pipe shall be connected
with the house drain or sewer. Such pipes must first discharge into a
proper condensing tank, and from this a proper outlet to the house
sewer outside of the building must be provi