oated.
Thin lead pipe; not heavy enough to withstand the bending and drawing
it is subjected to.

_Location and Position._--Pipes may be located within the walls and
built in, in which case they are inaccessible, and may be defective
without anyone being able to discover the defects. Pipes may be laid
with a wrong or an insufficient fall, thus leaving them unflushed, or
retarding the proper velocity of the flow in the pipes. Pipes may be
put underground and have no support underneath, when some parts or
lengths may sink, get out of joint, and the sewage run into the ground
instead of through the pipes. The pipes may be so located as to
require sharp bends and curves, which will retard the flow in them.

_Joints._--Joints in pipes may be defective, leaking, and not
gas-tight because of imperfect calking, insufficient lead having been
used; or, no oakum having been used and the lead running into the
lumen of the pipe; or, not sufficient care and time being taken for
the work. Joints may be defective because of iron ferrules being used
instead of brass ferrules; through improperly wiped joints; through
bad workmanship, bad material, or ignorance of the plumber. Plumbers
often use T branches instead of Y branches; sharp bends instead of
bends of forty-five degrees or more; slip joints instead of
lead-calked ones; also, they often connect a pipe of larger diameter
with a pipe of small diameter, etc.

_Traps._--The traps may be bad in principle and in construction; they
may be badly situated or connected, or they may be easily unsealed,
frequently obstructed, inaccessible, foul, etc.

_Ventilation._--The house drain may have no fresh-air inlet, or the
fresh-air inlet may be obstructed; the vent pipes may be absent, or
obstructed; the vertical pipes may not be extended.

_Condition._--Pipes may have holes, may be badly repaired, bent, out
of shape, or have holes patched up with cement or putty; pipes may be
corroded, gnawed by rats, or they may be obstructed, etc.

The above are only a few of the many defects that may be found in the
plumbing of a house. It is, therefore, of paramount importance to have
the house plumbing regularly, frequently, and thoroughly examined and
inspected, as well as put to the various tests, so as to discover the
defects and remedy them.

=Plumbing Tests.=--The following are a few minor points for testing
plumbing:

(1) To test a trap with a view to finding out whether its seal is lost
or