with an inclination toward the exit; on
one end of the trough there is a socket fitted with a plug, and on the
other a flushing apparatus consisting simply of a water service-pipe.
Above the iron trough brick walls are built up, inclosing it; over it
are placed wooden seats, and surrounding the whole is a wooden shed
with compartments for every seat. The excreta are allowed to fall into
the trough, which is partly filled with water, and once a day, or as
often as the caretaker chooses, the plug is pulled up and the excreta
allowed to flow into the sewer with which the school sink is
connected. These school sinks are, as a rule, a nuisance, and are
dangerous to health. The objections to them are the following:

(1) The excreta lies exposed in the iron trough, and may decompose
even in one day; and it is always offensive.

(2) The iron trough is easily corroded.

(3) The iron trough, being large, presents a large surface for
adherence of excreta.

(4) The brickwork above the trough is not flushed when the school sink
is emptied, and excreta, which usually adheres to it, decomposes,
creating offensive odors.

(5) The junction of the iron trough with the brickwork, and the
brickwork itself, is usually defective, or becomes defective, and
allows foul water and sewage to pass into the yard, or into the wall
adjacent to the school sink. By the Tenement House Law of New York,
the use of school sinks is prohibited even in old buildings.

[Illustration: FIG. 29.

SCHOOL SINK AFTER SEVERAL MONTHS' USE.

(J. SULLIVAN.)]

_Yard Hopper Closets._--Where the water-closet accommodations cannot,
for some reason, be put within the house, yard hopper closets are
commonly employed. These closets are simply long, iron-enameled
hoppers, trapped, and connected with a drain pipe discharging into
the house drain. These closets are flushed from cisterns, but, in such
case, the cisterns must be protected from freezing; this is
accomplished in some houses by putting the yard hopper near the house
and placing the cistern within the house; however, this can hardly be
done where several hoppers must be employed. In most cases, yard
hoppers are flushed by automatic rod valves, so constructed as to
flush the bowl of the hopper whenever the seat is pressed upon. These
valves, as a rule, frequently get out of order and leak, and care must
be taken to construct the vault under the hopper so that it be
perfectly water-tight. An improved form of