Renard’s own graceful ship attained a speed of but half that much. In order, therefore, to give his vessel the desired usefulness its speed must be doubled. This would require an eightfold[11] increase of motive power without increase of weight. Evidently then the cardinal requisite was a light durable motor of extraordinary output. Such motors fortunately were now coming into the market, owing to the development of gasoline engines for automobile racing.
The year 1898 witnessed the commencement of two famous systems of navigation by the lighter than air, one in France, the other in Germany, destined quickly to revolutionize the art, and to establish it on a practical basis. The leading exponents of these two systems were Señor Don Alberto Santos-Dumont, a rich young Brazilian living in Paris, and Count Ferdinand von Zeppelin, Germany’s stanch old admiral of the air. Both achieved success by applying the gasoline engine to the propulsion of elongated balloons, but by very different methods. Santos-Dumont, apparently ignoring, or fearing to adopt, the excellent hull and car designed and used by Renard, began where Tissandier left off, with a symmetrical hull and low-hung car, thus producing a safe aërial pendulum, if not a racing machine; then by degrees he gradually felt his way to something more efficient. Zeppelin began with a long cylindrical hull pointed at the ends, rigidly framed like that of Schwartz, and supporting its car and propellers well aloft near the line of resistance. His was a bold and effective design but difficult to execute. Santos-Dumont scored the first success, and startled the world by his spectacular flights; but ere long he was surpassed by other builders of non-rigid balloons. Zeppelin won his success slowly and by heroic perseverance in the face of enormous obstacles, finally emerging as the most successful and illustrious figure in the history of aëronautics. The achievements of these two pioneers and colleagues make the first decade of the twentieth century memorable in the annals of aërial navigation.
Santos-Dumont, who spent his early years on his father’s large coffee plantation in Brazil, had, during boyhood, dreamed of navigating the air, and in 1897, at the age of twenty-four, made in France his first ascension in a spherical balloon. While living at Paris during that year he gave much time to motorcycling, automobiling and operating spherical balloons, of which he possessed two constructed after his own ideas; one, the smallest in the world, designed for solitary voyages, the other large enough for more than one person, intended for social excursions. Thus by way of amusement, and probably by impulse rather than deliberate purpose, he was equipping himself to become both the designer and the pilot of his future dirigibles.
Having acquired experience and skill in operating both balloons and engines, the young enthusiast set about realizing his boyhood dream of navigating the air independently of the course of the wind. His first dirigible was designed to carry his weight of 110 pounds and a 3½ horse-power petroleum engine taken from his tricycle, and reduced in weight to 66 pounds. The hull was a cylinder of varnished Japanese silk, 82½ feet long including its pointed ends, 11½ feet in diameter and 6,354 cubic feet in gas capacity. A ballonet, or air pocket, occupied the lower middle of the envelope. The basket for the little pilot, engine, and two-blade propeller was suspended far below the hull, to which its cords were attached by means of small wooden rods inserted into hems along each side of the envelope, for a great part of its length. The poise of the vessel was controlled by shifting weights fore and aft, while the turning right and left was effected by means of a silk rudder stretched over a steel frame. On the whole it was a crude and primitive affair, but of considerable interest as the first dirigible of a young man destined to give a strong impulse to the development of motor balloons of the non-rigid type.
After some preliminary tests, the little air ship and pilot soared away from the Zoölogical Garden in Paris, on September 20, 1898, rising in the face of a gentle wind, to the wonder and delight of a large crowd of witnesses, some of them professional aëronauts and very skeptical as to the outcome of this venturesome experiment. The ship maneuvered round and round overhead of the applauding throng, steering readily in all directions. Then the green navigator ascended a quarter of a mile and merrily continued his evolutions in the direction of the Longchamps race course. But when he wished to descend he observed the envelope contracting in volume, and was appalled to find that he could not pump air into the ballonet fast enough to keep the hull distended. It became swaybacked, and “all at once began to fold in the middle like a pocket-knife; the tension cords became unequal and the balloon envelope was on the point of being torn by them.” As he was falling swiftly toward the grassy turf at Bagatelle, he called to some boys who were flying kites, to grasp his guide-rope and run against the wind. They understood and ran so swiftly with the canted balloon that it played kite, and descended with a moderated fall, landing the frightened aëronaut safely on the turf.
Except for the doubling of his long balloon, Santos-Dumont’s first voyage was satisfactory, and he returned to Paris elated. He had found it easy to steer in all directions. He could change his level hundreds of feet without discharge of gas or ballast, by merely canting his balloon, and allowing it to run obliquely up or down grade. He had stemmed the wind and gone whither he pleased, at such speed as to make his clothes flutter. And best of all he had found no danger in using a gasoline motor near an inflammable gas bag. The mere buckling of the long bag was a trifle, to be remedied by using an air pump adequate to maintain the flabby thing well inflated. He felt, therefore, that he had the conquest of the air well in hand, and that he was drifting into air ship construction as a life work. Small wonder that he continued his conquests till he had built, in less than one decade, fourteen motor balloons.
Santos-Dumont No. 2 was closely patterned after its predecessor, but was a little larger and carried a rotary fan worked by the motor, to keep the balloon plump by filling the air pocket, or ballonet. On May 11, 1899, an ascension was made from the old starting place, but in rainy weather. As the vessel rose its hull contracted faster than air could be pumped into the ballonet, the long bag doubled worse than before, and dropped into the trees with its chagrined but fearless rider.
The No. 3, which followed, was a short, thick vessel, 66 feet long by 25 feet in diameter, having in outward appearance the features of Dupuy de Lome’s very stable and very slow dirigible. It was apparently a safety ship for a scared young man who had not yet learned fully to appreciate Renard’s elegant design. It served for a few pleasant trips, while the inventor was screwing up courage to build another cylindrical vessel, and gradually realizing the advantage of an elongated car such as Renard had employed in La France. Not only was the hull short and thick, but it was further secured from buckling by a horizontal stiffening pole placed between it and the basket, and from which the latter was hung. After some voyages in No. 3, which the captain found very tractable, and probably capable of fifteen miles per hour, he was ready to begin a new vessel.
The No. 4 was a compromise between the better features of No. 3 and its predecessors. The elongated hull and ballonet were resumed, and the stiffening pole was elaborated into a longish car resembling Renard’s, but of triangular cross section. On this long trussed frame were placed the motor, propeller, rudder and the rider in his basket. A seven horse-power engine turning, at one hundred revolutions per minute, a screw propeller having two blades, each 13 feet across, gave a thrust of 66 pounds. Frequent trials of the ship during the summer of 1900, in presence of the Exposition crowds, brought the inventor into extraordinary prominence, and secured for him the “Encouragement Prize” of the Paris Aëro Club, consisting of the yearly interest on one hundred thousand francs, this being one of M. Deutsch’s numerous foundations for the promotion of aëronautics.
In the spring of 1900, M. Deutsch de la Meurthe had established another prize which Santos-Dumont now greatly coveted, and hoped ere long to win. This was a cash sum of one hundred thousand francs to be awarded by the Scientific Commission of the Aëro Club of France to the first dirigible that, between May 1 and October 1, 1900, 1901, 1902, 1903, 1904, should voyage from Saint Cloud to and around the Eiffel tower, and return within half an hour. The distance to the tower and back, not counting the turn, was nearly seven miles, and the estimated speed required to fulfill the conditions for winning the prize, even in calm weather, was 15½ miles per hour.