Boys' Second Book of Inventions. Baker Ray Stannard

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СКАЧАТЬ In 1883 another Frenchman, Tissandier, experimented with electricity, but, as his batteries had to be light enough to be taken up in the balloon, they proved effective only in helping to weigh it down to earth again. Krebs and Renard, military aëronauts, succeeded better with electricity, for they could make a small circuit with their air-ship, provided only that no air was stirring. Enthusiasts cried out that the problem was solved, but the two aëronauts themselves, as good mathematicians, figured out that they would have to have a motor eight times more powerful than their own, and that without any increase in weight, which was an impossibility at that time.

      Santos-Dumont saw plainly that none of these methods would work. What then was he to try? Why, simple enough: the petroleum motor from his automobile. The recent development of the motor-vehicle had produced a light, strong, durable motor. It was Santos-Dumont's first great claim to originality that he should have applied this to the balloon. He discovered no new principles, invented nothing that could be patented. The cigar-shaped balloon had long been used, so had the petroleum motor, but he put them together. And he did very much more than that. The very essence of success in aërial navigation is to secure light weight with great strength and power. The inventor who can build the lightest machine, which is also strong, will, other things being equal, have the greatest success. It is to Santos-Dumont's great credit that he was able to build a very light motor, that also gave a good horse-power, and a light balloon that was also very strong. The one great source of danger in using the petroleum motor in connection with a balloon is that the sparking of the motor will set fire to the inflammable hydrogen gas with which the balloon is filled, causing a terrible explosion. This, indeed, is what is thought to have caused the mortal mishap to Severo and his balloon. But Santos-Dumont was able to surmount this and many other difficulties of construction.

      The inventor finally succeeded in making a motor – remarkable at that time – which, weighing only 66 pounds, would produce 3½ horse-power. It is easy to understand why a petroleum motor is such a power-producer for its size. The greater part of its fuel is in the air itself, and the air is all around the balloon, ready for use. The aëronaut does not have to take it up with him. That proportion of his fuel that he must carry, the petroleum, is comparatively insignificant in weight. A few figures will prove interesting. Two and one-half gallons of gasoline, weighing 15 pounds, will drive a 2½ horse-power autocycle 94 miles in four hours. Santos-Dumont's balloon needs less than 5⅓ gallons for a three hours' trip. This weighs but 37 pounds, and occupies a small cigar-shaped brass reservoir near the motor of his machine. An electric battery of the same horse-power would weigh 2,695 pounds.

      Santos-Dumont tested his new motor very thoroughly by attaching it to a tricycle with which he made some record runs in and around Paris. Having satisfied himself that it was thoroughly serviceable he set about making the balloon, cigar-shaped, 82 feet long.

      "To keep within the limit of weight," he says, "I first gave up the network and the outer cover of the ordinary balloon. I considered this sort of second envelope, holding the first within it, to be superfluous, and even harmful, if not dangerous. To the envelope proper I attached the suspension-cords of my basket directly, by means of small wooden rods introduced into horizontal hems, sewed on both sides along the stuff of the balloon for a great part of its length. Again, in order not to pass the 66 pounds weight, including varnish, I was obliged to choose Japan silk that was extremely fine, but fairly resisting. Up to this time no one had ever thought of using this for balloons intended to carry up an aëronaut, but only for little balloons carrying light registering apparatus for investigations in the upper air.

      "I gave the order for this balloon to M. Lachambre. At first he refused to take it, saying that such a thing had never been made, and that he would not be responsible for my rashness. I answered that I would not change a thing in the plan of the balloon, if I had to sew it with my own hands. At last he agreed to sew and varnish the balloon as I desired."

      After repeated trials of his motor in the basket – which he suspended in his workshop – and the making of a rudder of silk he was able, in September, 1898, to attempt real flying. But, after rising successfully in the air, the weight of the machinery and his own body swung beneath the fragile balloon was so great that while descending from a considerable height the balloon suddenly sagged down in the middle and began to shut up like a portfolio.

      "At that moment," he said, "I thought that all was over, the more so as the descent, which had already become rapid, could no longer be checked by any of the usual means on board, where nothing worked.

      "The descent became a rapid fall. Luckily, I was falling in the neighborhood of the soft, grassy pélouse of the Longchamps race-course, where some big boys were flying kites. A sudden idea struck me. I cried to them to grasp the end of my 100-meter guide-rope, which had already touched the ground, and to run as fast as they could with it against the wind! They were bright young fellows, and they grasped the idea and the guide-rope at the same lucky instant. The effect of this help in extremis was immediate, and such as I had expected. By this manœuvre we lessened the velocity of the fall, and so avoided what would otherwise have been a terribly rough shaking up, to say the least. I was saved for the first time. Thanking the brave boys, who continued to aid me to pack everything into the air-ship's basket, I finally secured a cab and took the relic back to Paris."

      His life was thus saved almost miraculously; but the accident did not deter him from going forward immediately with other experiments. The next year, 1899, he built a new air-ship called Santos-Dumont II., and made an ascension with it, but it dissatisfied him and he at once began with Santos-Dumont III., with which he made the first trip around the Eiffel Tower.

      He now made ready to compete for the Deutsch prize of $20,000. The winning of this prize demanded that the trip from Saint-Cloud to the Eiffel Tower, around it and back to the starting place, a distance of some eight miles, should be made in half an hour. For this purpose he finished a much larger air-ship, Santos-Dumont V., in 1901. After a trial, made on July 12, which was attended by several accidents, the inventor decided to make a start early on the following morning, July 13. As early as four o'clock he was ready, and a crowd had begun to gather in the park.

      At 6.20 the great sliding doors of the balloon-house were pushed open, and the massive inflated occupant was towed out into the open space of the park. The big pointed nose of the balloon and its fish-like belly resembled a shark gliding with lazy craft from a shadow into light waters. In the basket of the car stood the coatless aëronaut, who laughed and chatted like a boy with the crowd around him.

      From the very first the conditions did not show themselves favourable for the attempt. The wind was blowing at the rate of six or seven yards a second. The change of temperature from the balloon-house to the cool morning air had somewhat condensed the hydrogen gas of the balloon, so that one end flapped about in a flabby manner. Air was pumped into the air reservoir, inside the balloon, but still the desired rigidity was not attained. But, more discouraging yet, when the motor was started, its continuous explosions gave to the practised ear signs of mechanical discord.

      Nevertheless, Santos-Dumont, with his sleeves rolled up, fixed himself in his basket. His eye took a careful survey of the entire air-ship lest some preliminary had been overlooked. He counted the ballast bags under his feet in the basket, he looked to the canvas pocket of loose sand at either hand, then saw to his guide-rope.

      There is a very great deal to look after in managing such a ship, and it requires a calm head and a steady hand to do it.

      "Near the saddle on which I sat," he writes, "were the ends of the cords and other means for controlling the different parts of the mechanism – the electric sparking of the motor, the regulation of the carburetter, the handling of the rudder, ballast, and the shifting weights (consisting of the guide-rope and bags of sand), the managing of the balloon's valves, and the emergency rope for tearing open the balloon. It may easily be gathered from this enumeration that an air-ship, even as simple as my own, is a very complex organism; and the work incumbent on the aëronaut is no sinecure."

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