It was estimated at the time of Dupuy de Lome's ascent, that had a steam-engine of a weight corresponding to that of the eight workmen been used, at least twice the power could have been obtained. But steam was considered too dangerous, and some other motive power which combined lightness with power seemed absolutely essential. The electric motor gave promise of success in this direction, and in 1883 the two Tissandier brothers in France applied such a motor to a balloon that was able to make headway against a seven-mile breeze, but was still far from fulfilling the requirements of an entirely dirigible balloon. Two years later the motor-driven balloon _La France_, of Renard and Krebs, attained a speed of fourteen miles an hour, and showed a distinct advance over all preceding models. Meanwhile motors were being reduced in weight and increased in power, and the hearts of aviators and balloonists were cheered by the fact that the light metal, aluminum, was steadily growing cheaper. Visions of an all-aluminum balloon were constantly before the minds of the inventors, and in 1894 such dreams took practical form in a balloon whose construction was begun by Herr Schwartz, under the auspices of the German Government. This balloon was of most complicated construction, depending for its lifting power upon the gas-filled aluminum tank, but utilizing for its steering-gear many of the features of the aeroplane. It was essentially a balloon, not a flying-machine, however, with a ten to twelve horse-power benzine-engine actuating four propelling screws. [Illustration: TWO FAMOUS FRENCH WAR BALLOONS. The lower figure the dirigible war balloon "La Patrie," which manœuvered on the Eastern boundary of France, and which was blown away and lost taking a northwesterly direction which probably landed it ultimately in the Arctic Sea--in 1908. The upper figure represents M. Deutsch's dirigible balloon "Ville de Paris" which was sent to the frontier to take the place of the lost "Patrie."] Before the balloon was completed Herr Schwartz died, but his plans were known to his wife, and, although considerably altered, were carried to completion. When all was finished, Herr Jaegels, an engineer who had had no experience as an aeronaut, volunteered to make an ascent and this metal ship-of-promise was launched. At first it rose rapidly and appeared to be making good progress against a strong wind; but suddenly it stopped, descended rapidly, and was smashed to pieces, the aeronaut saving himself by jumping just before it touched the ground. It developed later that he had lost control of the machine, simply because the machinery was too complicated for a single operator to handle. On discovering this, Herr Jaegels, confused for the moment, threw open the valve, causing the balloon to descend too rapidly. Thus the fruit of years of study and labor and the expenditure of fifty thousand dollars in money resulted in only about six minutes of actual flight.