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Scientific American, June 08, 1901
Boston Transcript, August 19, 1901
New York Herald, August 19, 1901
American Inventor letters to the editor penned by Whitehead and
editorial responses April, 1902
The Aeronautic World, May, 1903
Scientific American, September 19, 1903
Aviation History, March 1996
Air Enthusiast 35, January 1988
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EXPERIMENTS WITH MOTOR-DRIVEN AEROPLANES
Our illustrations depict experiments with an aeroplane carried
out recently by Mr. Gustave Whitehead, of Bridgeport, Conn., who
has been studying the subject of mechanical flight for upward
of fifteen years. In one of the pictures is shown a lightweight,
two cycle motor, which was used on the aeroplane in a recent experiment.
Unlike Lilienthal and Chanute, Whitehead does not attempt to soar
by jumping off a hill or precipice. He is content, on the contrary,
with flying near the ground; if he can only solve the problem
of rising from it quickly at will, and descending gently whenever
and wherever he wishes.
The method of soaring used by Mr. Whitehead consists in running
with the aeroplane against the wind, preceded by an assistant
who draws it with a rope when it leaves the ground. When sufficient
speed is attained, the operator, by tilting the aeroplanes slightly
upward, can leave the ground and skim along in the air, as shown
in one of the photographs. The trimming
of the aeroplanes, both longitudinally and transversely, is accomplished
by the operator shifting the position of his body, and the proper
trimming necessary to keep from taking a plunge is quite a delicate
matter. A puff of wind striking the aeroplanes harder on one side
than on the other can also easily upset their transverse stability,
unless the operator is quick to counteract it.
After practicing considerably at balancing the aeroplanes when
drawn by a man, Mr. Whitehead at length designed and built a lightweight,
two-cycle gasoline motor for propelling them. This motor is of
the air-cooled type, and has numerous loops of aluminum wire fastened
to the two cylinders in order to radiate the heat. The inventor
says that he has found aluminum to be much better for this purpose
than copper, which is the metal generally employed. The cylinders
of the motor have a 4-inch bore and a 4 4 1/2 inch stroke, and
it is designed to run at speeds of from 1,000 to 2,500 R. P. M.
It develops 12 horse power at the latter speed, and its weight
complete is but 54 pounds, or 4 1/2 pounds per horse power, which
shows it to be one of the lightest gasoline motors ever built.
Over 100 pounds compression is employed, the sole compression
space being the small dome on top of each cylinder, in the top
of which is seen the sparking plug. The motor, being of the two-cycle
type, is valveless, with the exception of light aluminum check
valves, through which the gas passes before making its entrance
into the sheet-steel crank case (which is divided by a central
partition) through the holes seen in its side. Splash lubrication
is employed in the crank case, and oil is fed to the cylinders
from two oil cups. A 25 inch wire wheel was used as a flywheel,
and carried fan blades for assisting in cooling the motor. Its
dimensions are 18 inches high by 12 inches long by 8 inches wide,
and in the experiments made with it, a two-bladed propeller 41/2
feet in diameter was fastened on the motor shaft and revolved
at a speed of 1,000 R. P. M. As the motor has four disk flywheels
inside its crank case, the large wire-spoked one is not absolutely
necessary, and in actual tests, when mounted on the aeroplanes,
the motor was found to work equally well without it, thus reducing
the total weight of the motor to 47 1/4 pounds.
The three aeroplanes are spaced 3 feet apart and are 16 feet long
by 5 feet wide. They are made up of spruce wood frames, covered
with muslin, and are suitably braced with diagonal wires. There
is a space in the center of the lower one for the operator, who
hangs from the two forward uprights and keeps the apparatus in
trim by shifting his body. A rigid, pyramidal-shaped rudder projects
from behind.
After ascertaining, by loading himself with sandbags, that the
aeroplanes were capable of lifting the extra weight of the motor
and propeller, the motor was attached to the two longitudinal
projecting rods of the lower aeroplane, and carried the propeller
in front of it on its c rank shaft By running with the machine
against the wind after the motor had been started, the aeroplane
was made to skim along above the ground at heights of from 3 to
16 feet for a distance, without the operator touching, of about
350 yards. It was possible to have traveled a much longer distance
without touching terra firm but for the operator's desire not
to get too far above it Although the motor was not developing
its full power, owing to its speed not exceeding 1,000 R. P. M.,
it developed sufficient to move the machine against the wind.
The total thrust, or, in this case, pull of the propeller was
found to be 280 pounds, while all that is needed to keep the machine
in the air, according to the dynamometric measurements made when
it was drawn by a man, is a pull of 28 pounds. Making the propellers
pull, instead of push the machine, aids greatly in maintaining
its stability.
Having proven that a less powerful motor will do the work, Mr.
Whitehead is now constructing one of 6 horse power which will
weigh between 25 and 30 pounds. He intends to drive two 4 1/2-foot
propellers with this, by means of bevel gears, giving the proper
speed reduction for obtaining a speed of 600 to 800 R. P. M. of
the propellers. Besides this smaller two cylinder motor,
he is also constructing a four-cylinder one, of 10 horse power,
which he expects will not exceed 40 pounds in weight, aluminum
being used as far as possible in its construction. This is to
be used on an improved aeroplane with which the inventor hopes
to be able to rise vertically in still air, travel horizontally,
and descend vertically again.
This is the desideratum of the aeroplane flying machine.
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