Evening star., 1894-12-14
BY COMP RESSED AIR
How the Atmosphere is Harnessed for Mans
Benefit
1t Cleans Cars, Runs Locomotives
Drills Rocks, Operates Clocks,
Calks Ships and Other Things.

From the Chicago Record.
Railroad passengers are frequently sur
prised by the unexpected entrance into
the cars of a group Of chatterins, bare
headed women. Those who do not recog-
nize them as car cleaners and busters won
der who they are and how they boarded
the train The women usually appear sew
eral blocks from the terminal station, and
so proficient are they in the art OF Zip
ping a train that the engineeF9s do not
come to a full stop when they~oee their
feather busters and brooms beside the
track, but reduce the speed somewhat,
and the women swing on as neatly as
brakemen. When the last passenger has
left the train the women take possession
muscular. quick with the broom and active
with the feather duster and chamois skin,
and by the time the cars are thrown on the
cleaning switch they have the floors we'll
cleaned of peanut shells, paper and cigar
stubs, and are ready for the seat cushions.
On some of the roads the women still
carry the cushions outside Of the car and
beat the dust from them by whipping them
with willow beaters. But compressed air
has taken the place of the paddle on most
of the roads. The hose which contains the
compressed air is run into the car through
window or door, and the women, han
ding it as they would a garden hose
sprinkling the grass, turn the jet of Kissing
air upon the plush cushions and the dust
leather strap or beater can get at the dust
as compressed air does. The jet searches
every crack and Granny and drives the
dust from the very wood itself. Sometimes
the women turn the air upon the window
casing and in a jiffy it Is clean of dust.
The man who makes air compressors
cited this novel use of compressed air as
another point in favor of the claim made
by his craft that compressed air was just
beginning to enter into the common every
day work of the world. He added that few
persons knew the uses to which compressed
air was put outside of stopping trains,
drilling rock and initiating bicycle tires.
Air Versus Electricity.
Electricians think that this is the elec-
trical age" he said. "Well, perhaps 1t is,
80 far as lightning, telephoning, telegraph
ing and welding goes, but when 1T comes
to the transmission of power they are
talking too much. They have worked and
studied for years to make an electric rock
drill which would take the place of the
air drill, but they have not succeeded.
They have tried to make an electric train
brake which would bring limited express
train to a full stop sooner than the auto
matte air brakes will do it. but they are
so far behind that they will never catch
up. 1t will not be long before street cars
will be running with compressed air
the motive power, and they will be safer,
more easily controlled, will run as fast,
Will stop quicker, VIII wear longer ana Will
be operated at less expense than the best
electric system they can put on the rails.
With good air compressor air at any
pressure can be stored up In a reservoir
or steel tank, and can be taken to any
point within reasonable distance eco
nomically and with less waste than cleo
tricity can be sent by WIRE
The air compressor is pump which is
part of a stationary engine. The piston
in the air chamber first sucks the air in
and then forces it through pipe to the
reservoir. OF course the more air one
pumps into the reservoir the greater pres
sure to the square inch one gets. The
compressed air works like steam, except
that it is cold and has not the expansive
qualities of steam. But steam cannot he
carried through pipes out of door to any
great distance, for 1t would lose its heat,
would condense and soon turn back to
water.
Cleaning cushions by compressed air is
one way of using ii that few people know
of. Visitors to the sanitary canal are al
ways Interested in the rock drills which
bore holes for the dynamite cartridges,
and almost everybody knows that the
brakes of passenger trains are operated
by compressed air.
Il know of machine shop where there
is not belt, piece OF shaftlnS or an
electric wire for all the machinery, from
little emery wheel to a twenty-ton crane,
L. operated by compressed air. The shop
is traversed by large pipes from the air
reservoir, and from these main pipes small
pipes lead down to the machines. Each
machine. whether drill, planer, shears,
lathe, bending rolls. milling machine,
has its own motor or engine. and the mere
turning Of a valve starts or stops the ma
chine.
For Clocks and Smoke.
"A pneumatic clock system has lately
been installed in the new Criminal Court
building In Chicago. Pneumatic clocks are
not new, for they have been used in Paris
N
clocks are operated and regulated from the
central clock by compressed air.
THE pneumatic clock system installed in
Paris twenty-five years ago was the begin
ming of the compressed air central power
system. which supplies over 10000 horse
power to users in the French capital. 1t is
used there for all purposes from running
clocks to operating dynamOs for electric
lights. The central station furnishes air at
a pressure of seventy-five pounds to the
square inch. 1t is sent around the city un-
der the streets in pipes, and is sold to Gus
toners by meter, just as gas Is.
The solution OF the smoke problem Is
easy. Put central power station where
the smoke will bother no one. and from this
station send electricity, high-pressure water
or compressed air to the business center
and to the stock yards. The cheapest pow
er that can be used in this way is COM
pressed air. Elevators, printing presses.
wood and iron working mac hinery, and. In
| fact, anything operated by steam, can be
operated by compressed air. Some day we
shall have pipes for compressed air under
| the pavements of streets. and there will re
| no smoke If the tugboats and locomotives
can be subdued."
| Asphalt used for street paving is refined
| by compressed air. In its original shape.
| just as it comes from Trinidad. asphalt 10
| too soft for street paving and Is not homo
| geneous To refine it the asphalt is boiled
\ in kettles for three or four days. and while
| the heat Is on IL must be constantly stirred.
| Pipes with numerous holes are placed In the
| bottom of the kettle. and while the asphalt
| is boiling compressed air is forced through
! the pipes. and, escaping through the holes.
| IL agitates the thick black stuff. At first
| the air comes to the surface in big bubbles,
| and the asphalt slObbers all over the inside
of the kettle, but at the end Of three days
| the asphalt has become so thin that the air
makes 1t boil in little bubbles. and 1t Is hen
irawn off In barrels, where 1t coOls hard
| and even.
| In France they make a sort Of silk from
| wood pulp by the aid of compressed air
| The wood pulp Is put through a chemical
tt.Ir,v