Garnerin's first practical test of his invention was made in October, 1797, when he ascended to the height of six thousand feet in a balloon to which was attached a parachute of the ordinary umbrella type still used. At that altitude he cut loose the balloon which rushed upward until it exploded, while the parachute, dropping rapidly at first, finally settled slowly and gently to the earth, without injury to the inventor.
PROGRESS IN MECHANICAL FLIGHT
The attempts at navigating a balloon having proved thus far so unsuccessful, many inventors now returned to the idea of producing a flying-machine which was independent of the inflated balloon. It was evident that the resistance presented by the great surface necessary in a balloon of sufficient size to have the required lifting power was such that no known efforts of propulsion could overcome this resistance even in the face of a slight breeze, to say nothing of a strong wind. The balloon was by no means abandoned, however, and two definite schools of aeronauts gradually came into existence, each having ardent advocates.
As early as 1784, the aeronaut Gérard had proposed a flying-machine which was to be made with body, wings, and steering apparatus, in which propulsion was to be accomplished by the use of escaping gas and gun-cotton. The inventor himself was so sanguine of the results, and so many contemporary inventors were of the same opinion, that when this machine proved to be an utter failure, the blow to the advocates of the flying-machine was so great that they did not rally from it for something like a quarter of a century. In 1809, however, a Viennese watchmaker named Degen revived interest in attempts at mechanical flight by inventing a flying-machine which consisted essentially of two parachutes. These were worked by hand, and the inventor was said to have been able to rise to a height of over fifty feet from the ground "moving in any desired direction."
These claims were not borne out in fact, but they stimulated an interest in the possibilities of mechanical flight, and in the parachute, which had never come into popular favor despite its successful use by the inventor, Garnerin. Hopes were again entertained that a modification of this device might be utilized in solving the problem of aerial flight, and in 1837 an aeronaut, Henry Cocking, invented a new type in which he proposed to descend from a balloon. The parachute of Garnerin, as we know, had been constructed like a huge umbrella, whereas Cocking's parachute had the general appearance of an umbrella held upside down. An unusual interest was aroused in the prospective experiment from the fact that a great majority of scientists did not consider that this parachute was constructed on correct scientific principles, and predicted that the aeronaut would be killed when he attempted to use it. Before the day of the trial arrived numerous articles had been published, presenting arguments for and against Cocking's device, and on the very day itself one of the newspapers contained a long article by a leading authority on aerostatics, reviewing the numerous reasons why the attempt would surely prove a failure.
Despite the protests of the majority of interested persons, however, Cocking and a companion named Green made the ascent at the appointed time. After rising to a certain height the parachute was cast off, the parachute's car containing the inventor, while Green remained in the balloon. Instead of sailing slowly toward the earth, however, the parachute fell rapidly, with an oscillating movement, gaining speed and jerking violently as it descended, until finally when several hundred feet in the air, Cocking was thrown from the car and dashed to pieces, while the wreck of the parachute landed a few yards away. Thus the predictions of the majority came true, although as we know now, the cause of the tragedy was due to faulty material rather than the design of the machine. For the American aeronaut, Wise, demonstrated a little later that parachutes built on the same principle as that of Cocking could be used successfully.
As we have seen, most of the flying-machines attempted heretofore took for their model the bird with flapping wings. There were certain persons, however, who had observed that this flapping movement was not essential to flight—that certain large-winged birds, such as buzzards and hawks, were able to soar in any direction at will, holding their wings rigidly. It was evident, therefore, that shape, position, and construction of the bird's wing played quite as important a part as the flapping movement. The lifting power of plane surfaces, or aeroplanes, was also carefully studied in this connection and in 1842 the inventor, Henson, constructed a flying-machine utilizing this aeroplane principle, his machine having thin, fixed surfaces, slightly inclined to the line of motion, and supported by the upward pressure of the air due to the forward movement.
Everyone will remember the distance to which a skilful juggler can project an ordinary playing-card by giving it a certain inclination in throwing. It will travel upward or on a level, and continue this direction until the force of the movement of throwing is exhausted. Obviously, if this force were self-contained in the card—if it could continue rotating and moving forward—it could fly indefinitely. Henson had studied and experimented with these miniature aeroplanes, and was convinced that if the same principle that governed their flight were to be applied to larger machines, practical flying-machines could be made.
"If any light and flat, or nearly flat, article," he wrote, "be projected edgeways in a slightly inclined position, the same will rise on the air till the force exerted is expended, when the article so thrown or projected will descend; and it will readily be conceived that if the article possessed in itself a continuous power or force equal to that used in throwing or projecting it, the article would continue to ascend so long as the forward part of the surface was upward in respect to its hinder part, and that such article, when the power was stopped, or when the inclination was recovered, would descend by gravity only if the power was stopped, or by gravity, aided by the force of the power contained in the article, if the power be contained, thus imitating the flight of a bird."
But when Henson attempted to fly in his elaborately planned and constructed flying-machine, it proved a complete failure. It showed a tendency to rise, but its lifting power was insufficient for the weight of the engine driving the propellers. It was evident, however, that if the power of the engine could be sufficiently increased, or, what amounts to the same thing, its weight sufficiently lightened, a machine built on the aeroplane principle could be made to fly. But at that time the lightest type of engine was a crude, heavy machine, and for the moment nothing more was attempted in producing a mechanical flying-machine propelled by steam.