. In the development
of these fixtures, as soon as a bad feature was recognized the
fixture was at once discarded, until now the market offers fixtures
as mechanically fine as can be produced. Plumbing fixtures were at
first manufactured so that it was necessary to support them on a
wooden frame, and this frame was enclosed in wood. The enclosure
made by this framework soon became foul and filthy and a breeding
place for all kinds of disease germs and vermin. This bad feature
was overcome by the introduction of open plumbing, that is,
fixtures so made that the enclosure of wood could be done away
with. The open plumbing allowed a free circulation of air around
the fixture and exposed pipes, thereby making the outside of the
fixture and its immediate surroundings free from all the bad
features of the closed plumbing. Plenty of fresh air and plenty of
light are necessary for good sanitary plumbing.

The materials of which the first open-plumbing fixtures were made
consisted of marble, copper, zinc, slate, iron, and clay. Time soon
proved that marble and slate were absorbent, copper and zinc soon
leaked from wear, iron rusted, and clay cracked and lacked
strength; therefore these materials soon became insanitary, and
foul odors were easily detected rising from the fixture. Besides
these materials being insanitary, the fact that a fixture was
constructed using a number of sections proved that joints and seams
were insanitary features on a fixture. For instance, in a marble
lavatory constructed by using one piece for the top, another for
the bowl, and still another for the back, filth accumulated at
every joint and seam. Following this condition, developed the iron
enameled and earthenware fixtures, constructed without seams and
with a smooth, even, glossy white finish. The fact that these
fixtures are made of material that is non-absorbent adds to their
value as sanitary plumbing fixtures.

[Illustration: FIG. 1.--Pan closet (_English_).]

Another problem which is as important as the foregoing is the
proper flushing, that is, the supplying of sufficient water in a
manner designed to cleanse the fixture properly.

The development of sanitary earthenware illustrates how the above
problems were satisfactorily solved. In the city of London a law
compelling the use of drains was enforced, and in the early 70's
the effect of this law was felt in this country. The introduction
at this time of the mechanical water closet, kno