Evening star., 1896-08-06
AIR MOTORS IN ACTUAL USE
A Washington Man Makes a Journey on
One of Them.
Description of the Car Now Being
Tried in New YOrk-GOOd Speed,
hut Severe vibration.

Inc star To-Day received tne 1OlO"iHS let
ter, that will doubtless be read with interest
in this city:
To the Editor OF The Evening Star:
came over here last night for the ex-
press purpose Of seeiEg real live air motor
in practical operation. not motors of the
shrunken shank, trarsparent-rib variety.
such as are daily exhibited on the streets
of Washington, but the kind we have read
so much about for the past year or two IN
scientific magazines and newspapers, and
spent several hours today riding on one of
II EN- from Fort Lee Ferry to Harlem river,
ever the 12Jth street branch of the I'd ave-
rue railway, a distance of about two and
a quarter miles.
There are three compressed air motors
row in actual service on this line, but only
one of them is in use at time. They are
of the Hardie system and were built at
Rome, ~ Y, for the American Air Power
Company, which was incorporated several
months ago. and Is represented to have a
capital stock of 81 100000. E. A. Willard is
president. Edward Comstock. vice pres-
dent; Henry Marquand. treasurer; Samuel
Lee. secretary: Henry D. Cooke, son of
the late Gov Cooke of Washington, general
manager, and E. f. Pettee, engineer.
Appearance of the Car.
In size, appearance and finish these cars
resemble those of the Columbia line in
Washington, although somewhat higher.
They are % feet in length over all. weigh
Sh tons and seat about twenty-eight per-
sons. In each car there are sixteen air
reservoirs. with total capacity of fifty
one cubic feet. These reservoirs weigh in
the aggregate 4,?!0 pounds. There is one
under each seat running the entire length
of the car, and the others, varying in size,
are distributed under the floor of the car
They all rest on framework supported by
springs. They are said to be made in Ger
many of Mannesmann metal the finest form
of steel and it is claimed that the tubes in
the process of manufacture are rolled like
the Damascus steel barrels of a shotgun.
This process is said to give them great
strength. They are tested to a pressure of
I,30o pounds to the square inch, and bear
the stamp of the German government in
spector. 1t is claimed that If the pressure
of 1000 pounds to the square inch, to which
they are subjected while in actual use
should cause one of them to burst the metal
would simply split and let the air escape
but would not fly in pieces and do injury
This claim may be good in theory, but
would rather be somewhere else than sit
ting over one of them when 1t Is being
worked out in practice.
The heater used to warm the air before 1t
enters the cylinder to propel the car is
seven feet long ami eighteen inches in di-
aneter, and is always about half full of
water. through which the air is made to
pass. This cylinder is in the center of the
car Underneath the floor.
Motive Power.
There are two engines, one on each side
of the center Of the car. These are about
three feet long. with diameter of about
seven inches. The brake is applied by NOV
a small handle similar to that of an ensi-
neer's valve.
The interior of the car is the same in
fhn ,Ji,-,r
the mechanism Is underneath the seats and
floor and out of sight. There is nothing to
constantly remind the nervous passenger
tnat lhere is underneath the seat on which
ne sits and The floor which he rests his
feet stored power. the explosive force of
which Is two thousand pounds to the
square inch.
The cars are illuminated with the P.ntsch
hsht' there being three lamps in each car
Successful Run.
The short stretch of road on which
the experiment is now being made with
these air motors Is almost a straight line
without curves or grades the only grade
encountered being a short one of about a
hundred feet in length, where 12Jth street
is raised to cross over the tunnel of the
New York Central railroad This the car
passed over without apparent difficulty and
1t seems to have sufficient power to make
and maintain the speed of fifteen miles an
hour Claimed for 1t. 1t is started and STOP
ped easily. quickly and nciselessly, without
jerking or perceptible sound of escaping
air, and seems to be under perfect control
of the motorman.
Considerable Vibration,
There is, however, a great deal of yibra-
ton in its movement, giving an uncom-
Portable sensation, similar to but not as
great as that experienced when a car is
off the track. Mr.. Hardie, the inventor of
the system. who went over the line with me
on one of the trips, explained that this was
due to the newness and stiffness of the
springs, and that 1t would all disappear af-
ter the car has been in use awhile, and the
springs get limbered up.
1 doubt very much the correctness of
this theory, however, the machinery un-
derneath the car is very cumbersome and
complicated, and l think the trouble is in
that. Considerable improvement IN the rum
ming of the car will have to be made in
this respect before it will give general sat
isfactiOn or meet the demands of railroad
officials or the public. r. Z. KANE.
New York August = 1S!K