|
|
|
Model Aeronautics for Dodos
eLibrary
|
Chapter IV: Airships Of War( Page 5 ) Next >> Continued from page 4...... But although Great Britain and France apparently lagged behind the Germans, appreciable enterprise was manifested in another direction. The airship was not absolutely abandoned: vigilance was maintained for a superior type of craft. It was an instance of weighing the advantages against the disadvantages of the existing types and then evolving for a design which should possess the former without any of the latter. This end appears to be achieved with the Astra type of dirigible, the story of the development of which offers an interesting chapter in the annals of aeronautics. In all lighter-than-air machines the resistance to the air offered by the suspension ropes is considerable, and the reduction of this resistance has proved one of the most perplexing problems in the evolution of the dirigible. The air is broken up in such a manner by the ropes that it is converted into a brake or drag with the inevitable result that the speed undergoes a severe diminution. A full-rigged airship such as the Parseval, for instance, may present a picturesque appearance, but it is severely unscientific, inasmuch as if it were possible to eliminateor to reduce the air-resistance offered by the ropes, the speed efficiency might be raised by some sixty per cent and that without any augmentation of the propelling effort. As a matter of fact Zeppelin solved this vexatious problem unconsciously. In his monster craft the resistance to the air is reduced to a remarkable degree, which explains why these vessels, despite all their other defects are able to show such a turn of speed. It was this feature of the Zeppelin which induced Great Britain to build the May-fly and which likewise induced the French Government to stimulate dirigible design and construction among native manufacturers, at the same time, however, insisting that such craft should be equal at least in speed to the Zeppelins. The response to this invitation was the Spiess, which with its speed of 45 miles per hour ranked, until 1914, as one of the fastest dirigibles in the French service. In the meantime a Spanish engineer, Senor Torres, had been quietly working out a new idea. He realised the shortcomings of the prevailing types of airships some eleven years ago, and unostentatiously and painstakingly set out to eliminate them by the perfection of a new type of craft. He perfected his idea, which was certainly novel, and then sought the assistance of the Spanish Government. But his fatherland was not adapted to the prosecution of the project. He strove to induce the authorities to permit even a small vessel to be built, but in vain. He then approached the French Astra Company. His ambition was to build a vessel as large as the current Zeppelin, merely to emphasise the value of his improvement upon a sufficiently large scale, and to enable comparative data concerning the two designs to be obtained. But the bogey of expense at first proved insuperable. However, the French company, decided to give the invention a trial, and to this end a small "vedette" of about 53,000 cubic feet displacement was built.
<< Previous [ p1 ] [ p2 ] [ p3 ] [ p4 ] [ p5 ] [ p6 ] Next >> Model Aeronautics For Dodos
© |
|