PHILLIPS’ AËROPLANE.
On May 6, 1896, Dr. Langley launched the picturesque steam model, which, to his mind, first proved conclusively the practicability of mechanical flight. It was the crowning success, and, as he thought then, probably the termination of his aëronautic labors. “I have brought to a close,” says he, “the portion of the work which seemed to be peculiarly mine—the demonstration of the practicability of mechanical flight—and for the next stage, which is the commercial and practical development of the idea, it is probable that the world may look to others. The world, indeed, will be supine if it does not realize that a new possibility has come to it, and that the great universal highway overhead is now soon to be opened.”
As shown in [Plate XV], Langley’s first successful steam flying machine is a tandem monoplane[21] with twin screws amidships. It measures nearly 13 feet from tip to tip of its wings, about 16 feet along its entire length, and weighs with motor and propellers 30 pounds. The boiler weighs 5 pounds, the engine 26 ounces, and the power developed was between 1 and 1.5 horse power. The model is therefore somewhat larger than a large condor, and very much more powerful.
Being too small to carry a pilot, it was launched over water, to obviate wreckage on landing. The machine was capable of flying several miles continuously, but in the actual test on the Potomac River the flight was limited, in order to prevent the model passing beyond the shore. The flyer was placed on launching ways on the top of a houseboat, hurled rapidly forward by force of a spring, and liberated in space, with engine and propellers running at full speed. Its subsequent behavior has been graphically described by an eyewitness, Dr. Alexander Graham Bell, in the following passage, published in Nature, May 28, 1896:
“On the occasion referred to, the aërodrome, at a given signal, started from a platform about 20 feet above the water, and rose at first directly in the face of the wind, moving at all times with remarkable steadiness, and subsequently swung around in large curves of perhaps a hundred yards in diameter, and continuously ascending till its steam was exhausted, when at a lapse of about a minute and a half, and at a height which I judged to be between 80 and 100 feet in the air, the whole ceased turning, and the machine, deprived of the aid of its propellers, to my surprise did not fall, but settled down so softly and gently that it touched the water without the least shock, and was in fact immediately ready for another trial.
“In the second trial, which followed directly, it repeated in nearly every respect the actions of the first, except that the direction of its course was different. It ascended again in the face of the wind, afterward moving steadily and continually in large curves, accompanied with a rising motion and a lateral advance. Its motion was, in fact, so steady that I think a glass of water on its surface would have remained unspilled. When the steam gave out again it repeated for a second time the experience of the first trial when the steam had ceased, and settled gently and easily down. What height it reached at this trial I can not say, as I was not so favorably placed as in the first, but I had occasion to notice that this time its course took it over a wooded promontory, and I was relieved of some apprehension in seeing that it was already so high as to pass the tree tops by 20 or 30 feet. It reached the water in one minute and thirty-one seconds from the time it started, at a measured distance of over 900 feet from the point at which it rose.
PLATE XV.
LANGLEY’S STEAM MODEL.
(Courtesy Smithsonian Institution.)