The whole machine weighed 830 pounds, including the pilot; spread 1,040 square feet of wing surface; measured 48 feet from tip to tip, and 52 feet from the point of its bowsprit to the end of its tail; soared at a speed of about 33 feet a second and a ten-degree angle of flight, the wings arching one in eighteen at one fourth the distance from their front edge. The double rudder, at the extreme rear, measured 95 square feet in each of its component surfaces.
It is evident from these figures, very kindly furnished by Mr. Manly, the mechanical engineer in charge of the experiments, that such an aëroplane had every equipment needed for a steady flight of many hours in fair weather. A thrust of 490 pounds on well-designed surfaces should easily carry 500 pounds of gasoline in addition to the 830 pounds regular weight of ship and pilot. This would enable the machine to fly practically all day without renewal of supplies. It appears, therefore, that Professor Langley had, in 1903, a dynamic aëroplane quite the peer, in many respects, of the best that were developed during the first decade of aviation, and that a mere accident, which should be expected in such complex experimentation, deprived him of the credit of the first man-flight on an adequately controlled and powered machine. Quite true, he lacked launching wheels; but how easy to add these, since they were proposed many times. He omitted the front steering plane, but had a rear one serving the same purpose. The worst that can be said is that he needed the equivalent of torsion wings for lateral control; but in moderate weather he could have flown successfully without them, as Farman, Delagrange, Paulhan[44] have so fully demonstrated. Besides, Langley had already tested the torsion wing device, and contemplated using it on his large machine.
A second launching was attempted on the Potomac River near Washington, on December 8, 1903. This time the rear guy post was injured, crippling the rear wings, so that the aëroplane pitched up in front and plunged over backward into the water. After some repairs it was stowed away in the Smithsonian Institution, where its frame and engine are still intact, its wings having been injured in the wreck and discarded. The experiments were now abandoned for want of funds to continue them.
Notwithstanding that Professor Langley had contributed much to the science of aërodynamics, by his elaborate researches, and had really developed a machine capable of sustained flight, if properly launched, he was subjected to unmitigated censure and ridicule; for he had incurred the enmity of various journalists and wiseacres, partly by his official secrecy, and partly by that natural reticence which avoids premature publicity in important scientific enterprises. This irresponsible criticism, combined with the cessation of work which should have brought success, profoundly grieved him, and doubtless hastened his death. He had, however, the satisfaction of knowing that a few competent specialists appreciated his labors, and would continue them to abundant fruition. A few days before his death he had the gratification of receiving, from the newly formed Aëro Club of America, the following communication acknowledging the value of his efforts to promote aërial travel.
Resolutions of the Aëro Club of America
Adopted January 20, 1906.
“Whereas, our esteemed colleague, Dr. S. P. Langley, Secretary of the Smithsonian Institution, met with an accident in launching his aërodrome, thereby missing a decisive test of the capabilities of this man-carrying machine, built after his models which flew successfully many times; and whereas, in that difficult experiment, he was entitled to fair judgment and distinguished consideration because of his important achievements in investigating the laws of dynamic flight, and in the construction of successful flying models; therefore be it
“Resolved, That the Aëro Club of America, holding in high estimation the contributions of Dr. Langley to the science of aërial locomotion, hereby expresses to him its sincerest appreciation of his labors as a pioneer in this important and complex science; and
“Be it further resolved, That a copy of these resolutions be sent to the Board of Regents of the Smithsonian Institution and to Dr. Langley.”
This kindly message from America’s foremost aëronautic society brought a moment’s pleasure to the last hours of the illustrious scientist. “Professor Langley was on his deathbed when these resolutions were brought to his attention, and when asked what should be done with the communication, his pathetic answer was: ‘Publish it.’ To all who know his extreme aversion to publicity in any form, this reply indicates how keenly he felt the misrepresentation of the press.”[45]
Professor Langley’s progress with the “aërodrome” was due largely to the skill, energy and devotion of his designer and superintendent of construction, Mr. Charles M. Manly. This talented young graduate in mechanical engineering, of Cornell University, in 1898, went directly from the class room to assume the chief burden of Langley’s researches in aërodynamics, and his practical experiments in mechanical flight, remaining till their termination in 1904. He was the confidential secretary and adviser to his chief in that whole enterprise. When in 1900 Dr. Langley stood baffled before the greatest obstacle in aviation, unable to find any manufacturer, in America or Europe, who could furnish a practical engine of the desired power, lightness and durability, Manly came to his rescue with a design which guaranteed success and which resulted in the wonderful gasoline motor built in the Smithsonian shops. Finally when the aëroplane was ready to be launched, it was Manly who bore the long weeks of trial in the malarial region of Widewater, harassed by accidents and foul weather, not to mention the merry agents of the press; and it was he who twice rode the ponderous aërodrome, shot forth in mid air at the imminent risk of his life.
While Langley was building his great tandem monoplane, Wilbur and Orville Wright of Dayton, Ohio, were developing a biplane which was an improvement on the aërial glider of Chanute and Herring. This was to be their preliminary effort toward achieving continuous flight. Their first product, tried at Kitty Hawk, North Carolina, in the summer of 1900, is shown in [Plate XIX]. The chief points of departure from Chanute and Herring’s glider were (1) to place the rider prone on the lower surface, as first proposed and tried by Wenham, forty years’ previously; (2) to discard the vertical rudder; (3) to place the horizontal rudder forward, as done by Mattullath and Maxim; (4) to control the lateral balance by changing the impact angles of the wings, as recommended by the present writer in 1893. Of these four modifications the first was impractical for general use, though good for soaring and possibly racing; the second was unsatisfactory and later abandoned; the third was effective, and has been accepted by some aviators as an improvement, but rejected by others who prefer the rear[46] horizontal rudder; the fourth proved acceptable to them, as to various other inventors before and after them.
With this glider they made a number of satisfactory flights. The front rudder and the torsional wings proved adequate to control the craft in sailing straight ahead down the Kill Devil sand hills, near Kitty Hawk, N. C. In this, as in all their machines to the present date, sled runners, fixed under the machine, as proposed by Ader and others, were used for launching and landing. With a surface of 165 square feet, they could glide down a slope of 9.5° at a speed of 25 to 30 miles an hour. This showed only a moderate efficiency, but it was a beginning.