Page:Popular Science Monthly Volume 89.djvu/879

 Faster Than the Fastest Express Train

The new Curtiss biplane makes one hundred and nineteen miles an hour

Bv Carl Dioiislharli

���On account of its moderate size and its elimination of small exposed parts this biplane has speed and climbing power

��THE really formidable problem of the aeroplane of to-day is cutting down the resistance of its structure.

A ver>- meritorious solution of this problem is found in a new Curtiss biplane which has attained speed and climbing power way beyond the usual range of its allotted motor power. The accompanying picture reveals its points of difference. Raking the air by small parts is eliminated more than in any previous design. The new machine shows "smooth bulk" and properly shaped "streamline" (to use a hackne\'ed and often unjustified expression) from the spokeless wheels and their trian- gular-shaped "legs." An important excep- tion are the few struts which as triangular frames join the upper plane at its center to the body. There is only one bracing member on each side. This is a bulk\- strut running from the lower to the higher plane and inclined so as to be compression and tension member in one. Additional brac- ing is supplied by a similar but even more inclined strut running to the wheel-base. Hence the biplane is stayed like a mono- plane, and the design becomes very strong.

As the wheeled base must in an\' case form a strong downward projection, it should be made thus to ser\'e as a support for the wings and be therebv braced in

��turn against side strains in bad landings. All vibrating wires may be eliminated in this way, and hence an immense amount of head resistance. The new bulky bracing members do not \ ibrate. Their number and smooth shape permit the air to flow off easiK- cm all sides without being caught by man\- adjoining wires and other exposed details, as by a rake. The flaring of the main braces at their ends is necessan,' to distribute their support over the depth of the ribs. There is one more improve- ment. A circular hood which revolves with the propeller is placed in front of the radiator. It is open so as to draw in cool- ing air, but is so designed as to cut down resistance.

The machine offers a \er\- satisfactory solution of the "unsurmountable" problem of carrying much sorely needed wing-sur- face on an extremely fast racing machine. Former "racers" were the poorest climbers and \cr\' dangerous in starting and landing on account of dependence on unduly re- duced wing-area for speed. But the new Curtiss racer is useful all around. Its splendid pcrforinance — one hundred and nmeteen miles an hour — is entircK- due to its moderate size. Large machines, on account of inherent relative weakness, are hopelessly dependent on wirebracing.

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