Page:Popular Science Monthly Volume 90.djvu/386

 �William A. Sharpe in his motor goose which is a com- bination automobile, motor boat and flying machine

BEFORE an aeroplane can fly, it must be in motion. Therefore a prelimin- ary run upon the ground is necessary. Hence, every aeroplane is virtually an automobile and could be used as such if our roads were wide enough to accommo- date its wings. A hydroaeroplane is a flying machine which takes its running start on water. Hence, it must be a service- able water craft. Is it not possible to build a machine which will be automobile, motor boat and flying machine in one? William A, Sharpe, of Detroit, thinks so.

It is not a new idea to build a floatable automobile which can run into a river from the shore without a stop. But it is certainly a new idea to combine in one vehicle the properties of an automobile, a motor boat and a flying machine.

Mr. Sharpe's ve- hicle has a boat body which is mounted on regulation auto- mobile wheels, which is equipped with a rudder, and which is propelled by four air propellers. These air propellers are in reality feathering paddle-wheels such as have been often proposed for air craft.

Benbow used them on the dirigible with which he flew over the St. Louis World's Fair in 1904, for example.

The ordinary air propeller is usually mounted on an aeroplane at the rear or in front. Mr. Sharpe would mount his pro- pellers as the paddle-wheels of river steamers are mounted — that is, flat along the sides of the craft. In that position they un-

��The Motor Goose

She runs on the ground ; she swims in water ; and her inventor says she will fly-

��By Carl Dienstbach

doubtedly take up much less room than ordinary aeroplane propellers. By a simple adjustment of the me- chanism that controls the feathering, they can be made either to lift or propel, or perform both functions to a varying degree. To maintain the balance of the craft in flight, seems theoret- ically easy; for the lift at each of the four supporting points may be increased or reduced at will as the occasion may demand. As the boat, automobile, or flying ma- chine, whatever it may be called, is driven over roads or water, the lifting effect of the propellers would undoubtedly be conducive to high speed. But, can the propellers support a machine in the air? If you will study the accompanying photographs you will see that no supporting surfaces, such as wings, are provided. How then can the machine fly?

Perhaps you have seen a little toy which consists essentially of a horizontally mount- ed screw-propeller driven by a rubber band. When you tighten up the rubber band and release it, the propeller literally kicks the little toy up into the air. Such a machine is known as a heli- copter, or screw-flyer. No helicopter has ever been built bigger than this little toy — that is, a helicopter that will fly.

Mr. Sharpe intends

to rely upon the

helicopter principle

in order to get his

machine into the air.

Unfortunately, his propellers are smaller

than those of a helicopter's of equal size.

Even if they were of the right size and even

if they were mounted horizontally like

those of a true helicopter, it is doubtful if

he would get off the ground. Only one of

the blades of his propellers is effective at a

time, just like the paddles of a river

steamer. To get a substantial lifting grip

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��There are no supporting surfaces, such as wings. The machine would mount into the air by the helicopter, or screw-flyer, principle

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