PLATE I.—THE LANGLEY MACHINE.
This craft, a double monoplane, was launched from a platform over the river Potomac, loaded with a weight equivalent to that of a man. The trials were unsuccessful; but recently—after a lapse of many years—the Langley machine has been tested again, and has proved its ability to fly.
Ader next turned to steam-driven craft, and built a series of queer, bat-like machines, which he called “Avions,” one of which is illustrated in [Fig. 16]. Its wings were built up lightly and with great strength by means of hollow wooden spars, and had a span of 54 feet, being deeply arched. The whole machine weighed 1100 lbs., and was thus far smaller and lighter than Maxim’s mighty craft. To propel it, Ader used a couple of horizontal, compound steam engines, which gave 20 h.p. each and drew the machine through the air by means of two 4-bladed screws. The craft was controlled by altering the inclination of its wings, and also by a rudder, the pilot sitting in a carriage below the planes. In 1890, after its inventor had spent a large sum of money, the machine—which, unlike those of Phillips and Maxim, ran upon wheels and was free to rise—did actually make a flight, or rather a leap into the air, covering a distance of about fifty yards. But then, on coming into contact with the ground again, it was wrecked. Ader’s experiments were regarded by the French Government as being so important that he received a grant equalling £20,000 to assist him in continuing his tests; and this goes to show how, even from the first, the French nation was—by reason of its enthusiasm and imagination—able to appreciate what its inventors were striving to attain, and eager to encourage them in their quest. For just an opposite reason—because, that is to say, it had not this imagination nor intuition—England neglected her experimenters, or merely regarded their efforts with an amused tolerance, as though they were children playing with toys.
Fig. 16.—Ader’s “Avion.”
Ader’s greatest success came in 1897. With an improved machine, he obtained a flight through the air of nearly 300 yards; and this goes down to history as being the first ascent by a power-driven aeroplane having a man on board. Ader’s name will never be forgotten, and one of his machines is exhibited, as a relic beyond price, at the Institute of Arts and Science in Paris. But the flight ended in damage to the machine, as the other had done. A wind gust threatened to overturn the craft, its engines were shut off, and it descended so heavily that it was wrecked. Through constant difficulties in regard to motive power, and the heavy cost of his experimental work, Ader was unable to make a definite success, or produce a machine which could be called a practical craft. In his case again, as in that of Maxim, there was a great and apparently insurmountable defect. The aeroplane would rise; its engines and propellers would drive it through the air; but the steersman had not his machine under control: he had not, in a word, learned to fly. The prospect, therefore, was unpromising, because one machine after another might share the same fate—rising into the air, flying a hundred yards or so, and then over-balancing and crashing to earth: thus, in fact, might thousands of pounds be squandered.
But this stage of putting into practice what science had taught, although disheartening for those who passed through it, was still of value; it made a stepping-stone to the next. One of the men who thus laboured, without himself seeing his work brought to the goal of success, was Professor S. P. Langley, an American scientist connected with the Smithsonian Institution, and a man of original ideas and great resource. He made a methodical investigation of the action of lifting planes and the shape of propellers, using a large revolving table so that he could test the latter while they were moving through the air. Then he began building models which took a double monoplane form, as indicated by [Fig. 17], with wings set at dihedral or upturned angle. This uptilting of the wings was to give the models stability while in flight: and the fixing of planes at the dihedral angle was tested, by later experimenters, in regard to full-sized machines. But while it gave an undoubted stability when a craft was flying under fair conditions, it was declared by some experts to be a disadvantage in gusty winds. There seemed also a risk that a machine so built might slip sideways when upon a turn. But in some machines to-day a modified dihedral angle is used, and with satisfactory results.
