Читать книгу The Rise of the Flying Machine - Hugo Byttebier - Страница 25

The Dirigible Parachute

1884 was another important year in the evolution towards the conquest of the air. The early 1880s had seen a renewed interest in soaring flight and in 1883 de La Landelle, the indefatigable aeronautical visionary who had coined the word “aviation”, indicated that the “experimental study of aero-dynamics (l’aéro-dynamique) would constitute a new science” as indeed it did and still does.

In 1884, de La Landelle proposed yet another variant among the possibilities of achieving human flight. The classical concept had been to accelerate a winged vehicle by using a mechanical powerplant until flying speed was reached, but the powerplant was long in coming. Then it appeared that the power of the wind would provide the solution and this led to the theories about soaring flight that were being debated at that time.

What de La Landelle now suggested was the use of gravity as a source of power. Flight had always been considered as the conquest of gravity and now gravity was proposed as a means to conquer itself, as it were. The concept seemed a bit outlandish but de La Landelle was right because soaring uses gravity as the primary source of power.

In an article in L’Aéronaute of July 1884, de La Landelle pointed to the parachute — a very old concept which had already been studied by Leonardo da Vinci — that could be used for flying experiments. He referred to the already functional parachute Garnerin had used in 1797 and which Garnerin’s niece Elisa had learned to manipulate in such a way that she could direct its descent and, as de La Landelle explained, had thereby turned her parachute into a glider. “Together with the kite” wrote de La Landelle, “the instrument that the aviation school should study can be condensed into two words, ‘dirigible parachute’.”

De La Landelle envisaged a sort of combination of kite and parachute, which meant a kind of weighted kite like the one Cayley had already experimented with. De La Landelle thought that, by using a dirigible parachute, a simple way could be found to control a glider in flight. This was not at all a foolish idea; it was taken up in earnest five years later and led to the first flying experiments with full-sized machines.

A second pioneer to come up with a new proposal was de Louvrié, who in 1866 had already indicated his belief in the possibility of fixed-wing flight and was now thinking about wheeled undercarriages, large airfields and a low frontal area of the body to reduce drag.

In May 1884 he published an article describing a soaring glider with an articulated tail that, in his opinion, would stabilize the glider’s flightpath. He still believed in the power of the wind as a propelling force but otherwise his ideas were following correct lines.

Meanwhile in England a newcomer, Horatio Phillips, applied for patents on a whole series of curved wing-shapes on which he had done actual experiments in “artificial currents of air”, a precursor of the modern wind tunnel. He had found that a suitably curved wing could lift twice as much as a flat surface, hence his patent applications. Later (in 1890) he patented an aeroplane that was to use a series of superposed curved wings in the manner of the venetian blind. A small model, fitted with forty of the specified wings totalling 136 sq ft and powered by a steam engine of 200 lbs, was tethered to a central pole and driven along a circular track, just as Tatin had done in 1879.

In May 1893 Phillips’ model aeroplane was tested, but the total weight of the apparatus amounted to 330 lbs and the engine was obviously not powerful enough, so that a complete take-off was not achieved in spite of the efficient wing-shapes.