The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-12-26

or cause pain. Sold by ali druggists. 25 cents.
Prepared only by c. ]. Hood q CO.. Lowell. Mass.
was a little greater than that of the other
cars on the road.
How u Compressed Air Car Looks.
The Hardie cars employed in this exper-
mental work We're like ordinary cable cars
IN appearance. except that the space be
meath the body Of the car was protected by
aprons extending atong the sides. Be
hind these aprons, mounted on the car
trucks, were the storage chambers, con
nected with the running gear by PTS lions
similar TO those employed in steam locomo-
tives. An improvement on this driving ap-
paratus was effected in what is known as
the Hoadley motor, the one now IN use
and in cars of this pattern none of the
operating machinery is exposed 10 view.
BottIing the Air.
In the air power plant now building at
West Twenty-fourth street and Eleventh
avenue, New York the power is devel-
oped by what is described as a three-stage
compressor. In the first chamber the air
Is driven up 10 a pressure of about 100
pounds TO The square inch. 1t is then cooled
by water jacket and enters a second
cylinder where the pressure is increased.
The cooling process is repeated, and the air
passes TO the third chamber, where il is
driven up to the pressure of 800 pounds
TO the square INCH, at which il is to be
used. For the third lime the air is sub
jected to the cooling ana drying process,
after which it is conveyed TO series Of
connected Mannesmann steel TASKS, where
it is stored awaiting use. The purpose Of
the water jackets is to do away with the
heat which naturally accompanies the com
preston.
Each of the air motor cars is fitted with
a Mannessmann steel bottle" extending
lengthwise beneath the floor of the car.
This bottle is a long steel tube with a ca
pacity of 81 cubic feet. Before being placed
in the car it is tested 10 a resisting
strength of 5000 pounds to the square inch.
So that there viii be no danger of break
age under service conditions.
Charging the Cars with Air.
The empty cars are run up to the charg-
ing stand in the power house and connect
ed with the main storage chamber. Air is
admitted to the car flask until the desired
PRESSURE, 900 pounds-is registered by the
storage gauge. Then the connection is
broken, the air in the chambers being pre-
vented from escape by "a check valve, and
the car is ready for a journey of from IS
10 20 miles. The whole process of charg-
ing occupies only two minutes and in the
event of haste can be completed in less
than a minute so that it win not cause
delay even with a congested traffic.
While this charging process is going on
connection is established with another
chamber beneath the car and live steam
is introduced to this compartment until
temperature of 300 Fahrenheit is registered.
This device is one of the most important
improvements in the development of COM
pressed air traction. II makes possible the
relocating of the air before it is used, there
by increasing its efficiency 100 per cent
and making it possible for air to compete
with electricity in the item of expense.
AS the cold air leaves the bottle beneath
the car 1t passes through an automatic
valve which reduces the pressure from q,
coo pounds TO $50, the latter being the
pressure al which it is applied to the
motor. The air passes through the reduc-
ing valve 10 the hot wafer chamber, the
heat thus applied to it causing an expan-
sion which nearly doubles its working pow
er. That is to say, each cubic foot of air,
after being heated, carries the air twice
SIS far as it could if it remained cold.
Machinery Is Simple.
The motor mechanism consists of two
Hnk-moiiOn, reciprocating engines, hav-
ing cylinders seven inches in diameter and
a 14-inch stroke. The power is applied by
connecting and parallel rods direct to the
crank pins of the four driving wheels. The
entire weight of car and apparatus is
mounted on elliptic springs, which gives
a smoothness of motion not obtained in
the ordinary car Al the point where the
air is finally set free, the pressure Is so
slight that there is no sound of exhaust.
The only way in which the escaping cur
rent manifests itself Is by a little puff of
steam. such as is caused by ones breath
on a frosty morning. This, of course is
due to the difference In temperature be
tween the atmosphere and the air oper-
ating the motor.
According to its advocates, compressed
air possesses many points of superiority
for street traction over any other power
at present in use. Edward e. Pettee, the
consulting engineer of the air power COM
pany, says:
Advantages of Compressed Air.
Street railway engines have long de-
manded an independent motor-one that
should make each car automobiles that
an accident at a central power station
might not result in tying up the whole
system This is provided by compressed
air, and may be described as one of the
chief engineering advantages. Perhaps its
greatest recommendation from the point of
view of the pubic is its safety. In case OF
control, 1t exoels any other system that
know Of. The high pressure air is always
at command to set the wheels, and can he
applied by a simple wrist movement by
the motorman.
''The entire mechanism is simple and
does not require any special skin 10 Oper-
ate There is no noise. smoke nor odor.
The installation is much cheaper than
that required by electric power, thus ef-
fecting saving in interest charges. 1t
is never necessary to tear up the streets
in order TO extend the power The cars
can be run wherever there are tracks. In
all these particulars l believe compressed
air TO be the most satisfactory power yet
developed"
Whatever. advantages compressed air
possesses on the score of safety or esthetic
qualities The point which is likely to de-
termine its final acceptance or rejection
by railway capitalists is the matter of
cost as compared with other forms of
power. If 1t costs the railway company
less for each car mile run by compressed
air than IL does with any power al pres