NEW MOTORS AND DEVICES.
Since the first edition of this book was printed, early in 1910,
there has been a remarkable advance in the construction of
aeroplane motors, which has resulted in a wonderful decrease
in the amount of surface area from that formerly required.
Marked gain in lightness and speed of the motor has enabled
aviators to get along, in some instances, with one-quarter of
the plane supporting area previously used. The first Wri
biplane, propelled by a motor of 25 h.p., productive of a fair
average speed of 30 miles an hour, had a plane surface of 538
square feet. Now, by using a specially designed motor of 65
h. p., capable of developing a speed of from 70 to 80 miles an
hour, the Wrights are enabled to successfully navigate a machine
the plane area of which is about 130 square feet. This
apparatus is intended to carry only one person (the operator).
At Belmont Park, N. Y., the Wrights demonstrated that the
small-surfaced biplane is much faster, easier to manage in the
hands of a skilled manipulator, and a better altitude climber
than the large and cumbersome machines with 538 square feet
of surface heretofore used by them.
In this may be found a practical illustration of the principle
that increased speed permits of a reduction in plane area in
mathematical ratio to the gain in speed. The faster any object
can be made to move through the air, the less will be the
surface required to sustain a given weight. But, there
is a limit beyond which the plane surface cannot be reduced
with safety. Regard must always be had to the securing of
an ample sustaining surface so that in case of motor stoppage
there will be sufficient buoyancy to enable the operator to
The baby Wright used at the Belmont Park (N. Y.) aviation
meet in the fall of 1910, had a plane length of 19 feet 6 inches,
and an extreme breadth of 21 feet 6 inches, with a total surface
area of 146 square feet. It was equipped with a new Wright
8-cylinder motor of 60 h. p., and two Wright propellers of 8
feet 6 inches diameter and 500 r. p. m. It was easily the fastest
machine at the meet. After the tests, Wilbur Wright said:
"It is our intention to put together a machine with specially
designed propellers, specially designed gears and a motor which
will give us 65 horsepower at least. We will then be able,
after some experimental work we are doing now, to send forth
a machine that will make a new speed record."
In the new Wright machines the front elevating planes for
up-and-down control have been eliminated, and the movements
of the apparatus are now regulated solely by the rear, or
A Powerful Light Motor.
Another successful American aviation motor is the aeromotor,
manufactured by the Detroit Aeronautic Construction.
Aeromotors are made in four models as follows:
Model 1.--4-cylinder, 30-40 h. p., weight 200 pounds.
Model 2.--4-cylinder, (larger stroke and bore) 40-50 h. p.,
weight 225 pounds.
Model 3.--6-cylinder. 50-60 h. p., weight 210 pounds.
Model 4.--6-cylinder, 60-75 h. p., weight 275 pounds.
This motor is of the 4-cycle, vertical, water-cooled type.
Roberts Aviation Motor.
One of the successful aviation motors of American make, is
that produced by the Roberts Motor Co., of Sandusky, Ohio.
It is designed by E. W. Roberts, M. E., who was formerly
chief assistant and designer for Sir Hiram Maxim, when the
latter was making his celebrated aeronautical experiments in
England in 1894-95. This motor is made in both the 4- and
6-cylinder forms. The 4-cylinder motor weighs complete with
Bosch magneto and carbureter 165 pounds, and will develop
40 actual brake h. p. at 1,000 r. p. m., 46 h. p. at 1,200 and 52
h. p. at 1,400. The 6-cylinder weighs 220 pounds and will
develop 60 actual brake h. p. at 1,000 r. p. m., 69 h. p. at
1,200 and 78 h. p. at 1,500.
Extreme lightness has been secured by doing away with all
superfluous parts, rather than by a shaving down of materials
to a dangerous thinness. For example, there is neither an intake
or exhaust manifold on the motor. The distributing valve
forms a part of the crankcase as does the water intake, and
the gear pump. Magnalium takes the place of aluminum in
the crankcase, because it is not only lighter but stronger and
can be cast very thin. The crankshaft is 2 1/2-inch diameter
with a 2 1/4-inch hole, and while it would be strong enough in
ordinary 40 per cent carbon steel it is made of steel twice the
strength of that customarily employed. Similar care has been
exercised on other parts and the result is a motor weighing 4
pounds per h. p.
The Rinek Motor.
The Rinek aviation motor, constructed by the Rinek Aero
Mfg. Co., of Easton, Pa., is another that is meeting with favor
among aviators. Type B-8 is an 8-cylinder motor, the cylinders
being set at right angles, on a V-shaped crank case. It is water
cooled, develops 50-60 h. p., the minimum at 1,220 r. p. m., and
weighs 280 pounds with all accessories. Type B-4, a 4-cylinder
motor, develops 30 h. p. at 1,800 r. p. m., and weighs 130 pounds
complete. The cylinders in both motors are made of cast iron
with copper water jackets.
The Overhead Camshaft Boulevard.
The overhead camshaft Boulevard is still another form of
aviation motor which has been favorably received. This is
the product of the Boulevard Engine Co., of St. Louis. It is
made with 4 and 8 cylinders. The former develops 30-35 h. p.
at 1,200 r. p. m., and weighs 130 pounds. The 8-cylinder motor
gives 60-70 h. p. at 1,200 r. p. m., and weighs 200 pounds.
Simplicity of construction is the main feature of this motor,
especially in the manipulation of the valves.