In the meantime, a new idea had been brought to the stage of actual trial. In 1893, in St. Petersburg, David Schwartz built a rigid airship, the gas receptacle of which was sheet aluminum. It was braced by aluminum tubes, but while being inflated the interior work was so badly broken that it was abandoned.
Schwartz made a second attempt in Berlin in 1897. The airship was safely inflated, and managed to hold its position against a wind blowing 17 miles an hour, but could not make headway against it. After the gas had been withdrawn, and before it could be put under shelter, a severe windstorm damaged it, and the mob of spectators speedily demolished it in the craze for souvenirs of the occasion.
Wreck of the Schwartz aluminum airship, at Berlin, in 1897.
The type of the earlier Santos-Dumont dirigibles. This shape showed a tendency to “buckle,” or double up in the middle like a jackknife. To avoid this the later Santos-Dumonts were of much larger proportional diameter amidships.
In 1898, the young Brazilian, Santos-Dumont, came to Paris imbued with aeronautic zeal, and determined to build a dirigible balloon that would surpass the former achievements of Giffard and Renard, which he felt confident were but hints of what might be accomplished by that type of airship. He began the construction of the series of dirigible balloons which eventually numbered 12, each successive one being an improvement on the preceding. He made use of the air-bag suggested by Meusnier for the balloon of the Duke of Chartres in 1784, although in an original way, at first using a pneumatic pump to inflate it, and later a rotatory fan. Neither prevented the gas-bag from “buckling” and coming down with consequences more or less serious to the airship—but Santos-Dumont himself always escaped injury. His own record of his voyages in his book, My Air-Ships, gives a more detailed account of his contrivances and inventions than can be permitted here. If Santos-Dumont did not greatly surpass his predecessors, he is at least to be credited with an enthusiasm which aroused the interest of the whole world in the problems of aeronautics; and his later achievements in the building and flying of aeroplanes give him a unique place in the history of man’s conquest of the air.
Type of the later Santos-Dumont’s dirigibles.
In 1900, Count von Zeppelin’s great airship, which had been building for nearly two years, was ready for trial. It had the form of a prism of 24 sides, with the ends arching to a blunt point. It was 420 feet long, and 38 feet in diameter. The structure was rigid, of aluminum lattice work, divided into 17 compartments, each of which had a separate gas-bag shaped to fit its compartment. Over all was an outer envelope of linen and silk treated with pegamoid. A triangular keel of aluminum lattice strengthened the whole, and there were two cars of aluminum attached to the keel. Each car held a 16 horse-power Daimler gasoline motor, operating two four-bladed screw propellers which were rigidly connected with the frame of the ship a little below the level of its axis. A sliding weight was run to either end of the keel as might be required to depress the head or tail, in order to rise or fall in the air. The cars were in the shape of boats, and the ship was built in a floating shed on the Lake of Constance near Friedrichshafen. At the trial the airship was floated out on the lake, the car-boats resting on the water. Several accidents happened, so that though the ship got up into the air it could not be managed, and was brought down to the water again without injury. In a second attempt a speed of 20 miles an hour was attained. The construction was found to be not strong enough for the great length of the body, the envelope of the balloon was not sufficiently gas tight, and the engines were not powerful enough. But few trips were made in it, and they were short. The Count set himself to work to raise money to build another ship, which he did five years later.