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572 ILLUSTRATED WORLD
AIR NOZZLE
GLASS COVER SL1
AIR OILSILK VALVES
NOZZLE
HOLDER
DUST CAPSULE
GASKETS LEATHER PLUNGER
SECTION THROUGH AIR PUMP
In itself, this new dust counter is an
unimpressive thing, considering the work
it is designed to do. In brief, it looks
and acts like a large brass syringe—the
sort of instrument with which a stage
horse-doctor is equipped.
The character of the dust found in
various places, is widely different, from
the lint of a clothing factory, to the bits
of leaf in the air of a cigar-making
shop. The study of dust-particles in the
air is really so new a science, that conditions
in general are far from satisfactory.
An architect, who was supervising the
building of a moving picture theater,
applied at the building department for
permission to make his ventilating shaft,
which would convey fresh air to the
audience, of a patent wood-fiber board.
His reason was that a strike on the part
of the metal workers had made it impossible
to install a sheet metal ventilating
duct. A shaft of fiber-board, however,
could be built in by carpenters.
The question was submitted
to Dr. Hill, who felt of the
sample of material which the
HOLDER
GLASS COVER SLIP
WOOD HAN DLE
architect had brought with him. Then
he prepared his dust counter, set the
sample of fiber-board in front of a
swiftly moving electric fan, and pumped
several cubic inches of the air which was
blown along the fiber surface through
the counter.
The slip of glass was then put under
the microscope, and was shown to be
almost covered with minute, lint-like
fragments. Even the architect, who was
anxious to use the fiber-board because
of its inexpensiveness, was convinced by
one look into the microscope. With the
best intentions in the world for supplying
the prospective theater patrons with
fresh air, he would have succeeded only
in giving them an unwholesome amount
of dust to breathe. Arid the more fresh
air he tried to supply, the worse he
would hjai*e made conditions.
We ai^vtio longer concerned with the
mote in 'wur neighbors' eyes. But we
are concerned quite deeply over the
motes which they draw into
their lungs with each breath.
For we are breathing the
same air, and our health must
be protected.
Three Sample Gelatin Plates
The one at the left is a sample of air such as
you find on Colorado's mountain ranges. It contains
very little dust. At the right is a sample of
Chicago air, while the slide at the top shows a
piece of lint caught against the gelatin. This
specimen was taken in a woolen mill.
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