How It Flies; or, The Conquest of the Air. Richard Ferris
surfaces of aeroplanes, and his researches into the correct proportion of motive power to the area of such surfaces. Much of his results have not yet been put to practical use by designers of flying machines.
Phillips’s Flying Machine—built of narrow slats like a Venetian blind.
The year 1888 was marked by the construction by Sir Hiram Maxim of his great aeroplane which weighed three and one-half tons, and is said to have cost over $100,000. The area of the planes was 3,875 square feet, and it was propelled by a steam engine in which the fuel used was vaporized naphtha in a burner having 7,500 jets, under a boiler of small copper water tubes. With a steam pressure of 320 lbs. per square inch, the two compound engines each developed 180 horse-power, and each turned a two-bladed propeller 17½ feet in diameter. The machine was used only in making tests, being prevented from rising in the air by a restraining track. The thrust developed on trial was 2,164 lbs., and the lifting power was shown to have been in excess of 10,000 lbs. The restraining track was torn to pieces, and the machine injured by the fragments. The dynamometer record proved that a dead weight of 4½ tons, in addition to the weight of the machine and the crew of 4 men, could have been lifted. The stability, speed, and steering control were not tested. Sir Hiram Maxim made unnumbered experiments with models, gaining information which has been invaluable in the development of the aeroplane.
View of a part of Maxim’s aeroplane, showing one of the immense propellers. At the top is a part of the upper plane.
The experiments of Otto Lilienthal in gliding with a winged structure were being conducted at this period. He held that success in flying must be founded upon proficiency in the art of balancing the apparatus in the air. He made innumerable glides from heights which he continually increased until he was travelling distances of nearly one-fourth of a mile from an elevation of 100 feet. He had reached the point where he was ready to install motive power to drive his glider when he met with a fatal accident. Besides the inspiration of his daring personal experiments in the air, he left a most valuable series of records and calculations, which have been of the greatest aid to other inventors in the line of artificial flight.
Lilienthal in his biplane glider.
In 1896, Professor Langley, director of the Smithsonian Institution at Washington, made a test of a model flying machine which was the result of years of experimenting. It had a span of 15 feet, and a length of 8½ feet without the extended rudder. There were 4 sails or planes, 2 on each side, 30 inches in width (fore-and-aft measurement). Two propellers revolving in opposite directions were driven by a steam engine. The diameter of the propellers was 3 feet, and the steam pressure 150 lbs. per square inch. The weight of the machine was 28 lbs. It is said to have made a distance of 1 mile in 1 minute 45 seconds. As Professor Langley’s experiments were conducted in strict secrecy, no authoritative figures are in existence. Later a larger machine was built, which was intended to carry a man. It had a spread of 46 feet, and was 35 feet in length. It was four years in building, and cost about $50,000. In the first attempt to launch it, from the roof of a house-boat, it plunged into the Potomac River. The explanation given was that the launching apparatus was defective. This was remedied, and a second trial made, but the same result followed. It was never tried again. This machine was really a double, or tandem, monoplane. The framework was built of steel tubing almost as thin as writing paper. Every rib and pulley was hollowed out to reduce the weight. The total weight of the engine and machine was 800 lbs., and the supporting surface of the wings was 1,040 square feet. The aeroplanes now in use average from 2 to 4 lbs. weight to the square foot of sustaining surface.
About the same time the French electrician Ader, after years of experimenting, with the financial aid of the French Government, made some secret trials of his machine, which had taken five years to build. It had two bat-like wings spreading 54 feet, and was propelled by two screws driven by a 4-cylinder steam engine which has been described as a marvel of lightness. The inventor claimed that he was able to rise to a height of 60 feet, and that he made flights of several hundred yards. The official tests, however, were unsatisfactory, and nothing further was done by either the inventor or the government to continue the experiments. The report was that in every trial the machines had been wrecked.
The experiments of Lilienthal had excited an interest in his ideas which his untimely death did not abate. Among others, a young English marine engineer, Percy S. Pilcher, took up the problem of gliding flight, and by the device of using the power exerted by running boys (with a five-fold multiplying gear) he secured speed enough to float his glider horizontally in the air for some distance. He then built an engine which he purposed to install as motive power, but before this was done he was killed by a fall from his machine while in the air.
Plan of Chanute’s movable-wing glider.
Before the death of Lilienthal his efforts had attracted the attention of Octave Chanute, a distinguished civil engineer of Chicago, who, believing that the real problem of the glider was the maintenance of equilibrium in the air, instituted a series of experiments along that line. Lilienthal had preserved his equilibrium by moving his body about as he hung suspended under the wings of his machine. Chanute proposed to accomplish the same end by moving the wings automatically. His attempts were partially successful. He constructed several types of gliders, one of these with two decks exactly in the form of the present biplane. Others had three or more decks. Upward of seven hundred glides were made with Chanute’s machines by himself and assistants, without a single accident. It is of interest to note that a month before the fatal accident to Lilienthal, Chanute had condemned that form of glider as unsafe.
Chanute’s two-deck glider.
In 1897, A. M. Herring, who had been one of the foremost assistants of Octave Chanute, built a double-deck (biplane) machine and equipped it with a gasoline motor between the planes. The engine failed to produce sufficient power, and an engine operated by compressed air was tried, but without the desired success.
In 1898, Lawrence Hargrave of Sydney, New South Wales, came into prominence as the inventor of the cellular or box kite. Following the researches of Chanute, he made a series of experiments upon the path of air currents under variously curved surfaces, and constructed some kites which, under certain conditions, would advance against a wind believed to be absolutely horizontal. From these results Hargrave was led to assert that “soaring sails” might be used to furnish propulsion, not only for flying machines, but also for ships on the ocean sailing against the wind. The principles involved remain in obscurity.
During the years 1900 to 1903, the brothers Wright, of Dayton, Ohio, had been experimenting with gliders among the sand dunes of Kitty Hawk, North Carolina, a small hamlet on the Atlantic Coast. They had gone there because the Government meteorological department had informed them that at Kitty Hawk the winds blew more steadily than at any other locality in the United States. Toward the end of the summer of 1903, they decided that the time was ripe for the installation of motive power, and on December 17, 1903, they made their first four flights under power, the longest being 853 feet in 59 seconds—against a wind blowing nearly 20 miles an hour, and from a starting point on level ground.
Wilbur Wright gliding at Kitty Hawk, N. C., in 1903.
During 1904 over one hundred flights were made, and changes in construction necessary to sail in circles were devised. In 1905, the Wrights kept on secretly with their practice and development of their machine, first one and then the other making the flights until both were equally proficient. In the latter part of September and early part of October, 1905, occurred a series of flights which the Wrights allowed to become known to the