Aircraft and Submarines. Abbot Willis John
Чтение книги онлайн.
Читать онлайн книгу Aircraft and Submarines - Abbot Willis John страница 9
The craft with which the Brazilian first strove to win the Deutsch prize he called Santos-Dumont No. V. It was a cylinder, sharp at both ends, 109 feet long and driven by a 12-horse-power motor. A new feature was the use of piano wire for the support of the car, thus greatly reducing the resistance of the air which in the case of the old cord suspensions was almost as great as that of the balloon itself. Another novel feature was water ballast tanks forward and aft on the balloon itself and holding together twelve gallons. By pulling steel wires in the car the aviator could open the stop-cocks. The layman scarcely appreciates the very slight shift in ballast which will affect the stability of a dirigible. The shifting of a rope a few feet from its normal position, the dropping of two handfuls of sand, or release of a cup of water will do it. A humorous writer describing a lunch with Santos-Dumont in the air says: "Nothing must be thrown overboard, be it a bottle, an empty box or a chicken bone without the pilot's permission."
After unofficial tests of his "No. 5" in one of which he circled the Tower without difficulty, Santos-Dumont summoned the Scientific Commission for a test. In ten minutes he had turned the Tower, and started back against a fierce head-wind, which made him ten minutes late in reaching the time-keepers. Just as he did so his engine failed, and after drifting for a time his ship perched in the top of a chestnut tree on the estate of M. Edmond Rothschild. Philosophical as ever the aeronaut clung to his craft, dispatched an excellent lunch which the Princess Isabel, Comtesse d'Eu, daughter of Dom Pedro, the deposed Emperor of Brazil, sent to his eyrie in the branches, and finally extricated himself and his balloon – neither much the worse for the accident. He had failed but his determination to win was only whetted.
The second trial for the Deutsch prize like the first ended in failure, but that failure was so much more dramatic even than the success which attended the third effort that it is worth telling and can best be told in M. Santos-Dumont's own words. The quotation is from his memoir, My Airships:
And now I come to a terrible day – 8th of August, 1901. At 6:30 A.M. in presence of the Scientific Commission of the Aero Club, I started again for the Eiffel Tower.
I turned the tower at the end of nine minutes and took my way back to St. Cloud; but my balloon was losing hydrogen through one of its two automatic gas valves whose spring had been accidentally weakened.
I had perceived the beginning of this loss of gas even before reaching the Eiffel Tower, and ordinarily, in such an event, I should have come at once to earth to examine the lesion. But here I was competing for a prize of great honour and my speed had been good. Therefore I risked going on.
The balloon now shrunk visibly. By the time I had got back to the fortifications of Paris, near La Muette, it caused the suspension wires to sag so much that those nearest to the screw-propeller caught in it as it revolved.
I saw the propeller cutting and tearing at the wires. I stopped the motor instantly. Then, as a consequence, the airship was at once driven back toward the tower by the wind which was strong.
At the same time I was falling. The balloon had lost much gas. I might have thrown out ballast and greatly diminished the fall, but then the wind would have time to blow me back on the Eiffel Tower. I therefore preferred to let the airship go down as it was going. It may have seemed a terrific fall to those who watched it from the ground but to me the worst detail was the airship's lack of equilibrium. The half-empty balloon, fluttering its empty end as an elephant waves his trunk, caused the airship's stern to point upward at an alarming angle. What I most feared therefore was that the unequal strain on the suspension wires would break them one by one and so precipitate me to the ground.
Why was the balloon fluttering an empty end causing all this extra danger? How was it that the rotary ventilator was not fulfilling its purpose in feeding the interior air balloon and in this manner swelling out the gas balloon around it? The answer must be looked for in the nature of the accident. The rotary ventilator stopped working when the motor itself stopped, and I had been obliged to stop the motor to prevent the propeller from tearing the suspension wires near it when the balloon first began to sag from loss of gas. It is true that the ventilator which was working at that moment had not proved sufficient to prevent the first sagging. It may have been that the interior balloon refused to fill out properly. The day after the accident when my balloon constructor's man came to me for the plans of a "No. 6" balloon envelope I gathered from something he said that the interior balloon of "No. 5," not having been given time for its varnish to dry before being adjusted, might have stuck together or stuck to the sides or bottom of the outer balloon. Such are the rewards of haste.
I was falling. At the same time the wind was carrying me toward the Eiffel Tower. It had already carried me so far that I was expecting to land on the Seine embankment beyond the Trocadero. My basket and the whole of the keel had already passed the Trocadero hotels, and had my balloon been a spherical one it would have cleared the building. But now at the last critical moment, the end of the long balloon that was still full of gas came slapping down on the roof just before clearing it. It exploded with a great noise; struck after being blown up. This was the terrific explosion described in the newspaper of the day.
I had made a mistake in my estimate of the wind's force, by a few yards. Instead of being carried on to fall on the Seine embankment, I now found myself hanging in my wicker basket high up in the courtyard of the Trocadero hotels, supported by my airship's keel, that stood braced at an angle of about forty-five degrees between the courtyard wall above and the roof of a lower construction farther down. The keel, in spite of my weight, that of the motor and machinery, and the shock it had received in falling, resisted wonderfully. The thin pine scantlings and piano wires of Nice (the town where the idea of a keel first suggested itself) had saved my life!
After what seemed tedious waiting, I saw a rope being lowered to me from the roof above. I held to it and was hauled up, when I perceived my rescuers to be the brave firemen of Paris. From their station at Passy they had been watching the flight of the airship. They had seen my fall and immediately hastened to the spot. Then, having rescued me, they proceeded to rescue the airship.
The operation was painful. The remains of the balloon envelope and the suspension wires hung lamentably; and it was impossible to disengage them except in strips and fragments!
The later balloon "No. VI." with which Santos-Dumont won the Deutsch prize may fairly be taken as his conception of the finished type of dirigible for one man. In fact his aspirations never soared as high as those of Count Zeppelin, and the largest airship he ever planned – called "the Omnibus" – carried only four men. It is probable that the diversion of his interest from dirigibles to airplanes had most to do with his failure to carry his development further than he did. "No. VI." was 108 feet long, and 20 feet in diameter with an eighteen-horse-power gasoline engine which could drive it at about nineteen miles an hour. Naturally the aeronaut's first thought in his new construction was of the valves. The memory of the anxious minutes spent perched on the window-sill of the Trocadero Hotel or