Professor Morgan continued: “Thus far the aeronauts had used hot air with which to make their ascents, but the fire under the balloon was always dangerous and more than one fatal accident resulted therefrom. Hydrogen gas was far better, but more costly. Public subscriptions enabled two brothers named Robert, assisted by M. Charles, to construct a spherical balloon, twenty-eight feet in diameter, the silk envelope being covered with varnish, and the upper half inclosed in a network which supported a hoop that encircled the middle of the sphere. A boat-like structure dangled a few feet below the mouth, and was attached to the hoop, while a safety valve at the apex prevented bursting through expansion of the gas as the balloon climbed the sky.
“This structure was inflated with hydrogen gas in the Garden of the Tuileries, Paris, on the first of December, 1783. M. Charles and one of the Roberts seated themselves in the car, provided with extra clothing, provisions, sand bags for ballast, a barometer and a thermometer, and gave the word to let go. The balloon soared swiftly, the aeronauts waving hands and hats in response to the cheers of the multitudes below. The ascent was a success in every respect. Having drifted thirty miles from Paris, the balloon safely descended near Nesle. There was so much gas left that the enthusiastic M. Charles decided to go up again, after parting with his companion. He climbed nine thousand feet and then by the dexterous use of his ballast came to earth again without the least jar.
“The impulse thus given to ballooning spread to other countries and it would be idle to attempt any record of their efforts. It may be said that for nearly a hundred years little or no progress was made in aerostation. Then came the second stage, the construction of dirigible or manageable balloons. All the structures which had hitherto left the earth were wholly under control of air currents, as much as a chip of wood is under the control of the stream into which it is flung. People began to experiment with a view of directing the course of the ships of the sky. While it was impossible to make headway against a gale or strong wind, it seemed that the aeronaut ought to be able to overcome a moderate breeze. The first attempt was by means of oars and a rudder, but nothing was accomplished until 1852, when Giffard used a small engine, but the difficulty of constructing a light motor of sufficient power checked all progress for awhile. It could not do so for long, however, as the inventive genius of mankind was at work and would not pause until satisfied. One of Giffard’s stupendous ideas was a balloon more than a third of a mile long with an engine weighing thirty tons, but the magnitude and expense involved were too vast to be considered.
“It would be tedious to follow the various steps in dirigible ballooning. It was not until 1882, that the Tissandier brothers, Gilbert and Albert—Frenchmen—built a dirigible cigar-shaped balloon substantially on the old lines, but it could not be made to travel more than five miles an hour in a dead calm, and was helpless in a moderate wind. None the less their attempts marked an epoch, for they introduced an electric motor. The ‘La France,’ when constructed some time later, was a hundred and sixty-five feet long, twenty-seven feet at its greatest diameter, and had a capacity of sixty-six thousand cubic feet. Many changes and improvements followed and an ascent was made in August, 1884, during which the balloon traveled two and a half miles, turned round and came back in the face of a gentle breeze to its starting point, the whole time in the air being less than half an hour. This was the first exploit of that nature.
“But,” added the Professor, “I am talking too much about dirigible ballooning, for our chief interest does not lie there. I am sure you have read of the Schwartz aluminum dirigible; Santos-Dumont and his brilliant performances with his fourteen airships; Roze’s double airship, and Count Zeppelin’s splendid successes with his colossal dirigibles.
“We have dealt only with structures that were lighter than air. The wonderful field that has opened before us and into which thousands are crowding, with every day bringing new and startling achievements, is that of the heavier-than-air machines. In other words, we have learned to become air men and to fly as the birds fly.
“Success was sure to come sooner or later, and when it did come every one wondered why it was so late, since the principles are so simple that a child can understand them. Otto Lilienthal, after long study and experimentation, published in Berlin in 1889, as one of the results of his labors, the discovery that arched surfaces driven against the wind have a strong tendency to rise. Then he demonstrated by personal experiments that a beginning must be made by ‘gliding’ through the air in order to learn to balance one’s self. He piled up a lot of dirt fifty feet high, and from its summit made a number of starts, succeeding so well that he tried a small motor to help flap his wings. Sad to say, an error of adjustment caused the machine to turn over in August, 1896, and he was killed.
“Percy S. Pilcher of England experimented for several years along the same lines and used the method of a kite by employing men to run with a rope against the wind, but he was destined to become another martyr, for he was fatally injured one day by a fall. Chanute and Herring of Chicago taught us a good deal about gliders. Herring used a motor driven by compressed air and had two plane surfaces for his apparatus, but his motor was too weak to sustain him for more than a few minutes.”
“Professor,” said Wharton, “I have often heard of the Hargrave kite; why do folks call it that name?”
“You mean the box pattern, made of calico stretched over redwood frames. They are the invention of Lawrence Hargrave of Sydney, Australia. He attached a sling seat to one and connected three above it. A brisk wind showed a lift of more than two hundred pounds, and he made a number of ascents, the kites preserving their stability most satisfactorily.