As Santos-Dumont thought his No. 4 scarcely swift enough to win the Deutsch prize, he enlarged it by inserting an additional length of sixteen feet at its middle, supplied it with a stronger car, and applied a larger engine, naming the new vessel so formed, his No. 5. Its hull was 109 feet long, 17 feet in largest diameter and cubed nearly 20,000 feet. A four cylinder air-cooled petroleum motor driving a screw propeller having two blades, each 13 feet across, gave a thrust of 120 pounds, at 140 revolutions per minute, and produced such draft as to give the inventor pneumonia. Among other novelties water ballast was used, and piano wires replaced the old-time suspension cords.
The No. 5 proved so powerful and swift that on July 13, 1901, Santos-Dumont attempted to win the Deutsch prize. Starting from the Aëro Club grounds at Saint-Cloud in presence of official witnesses, at half past six in the morning, when the air is usually stillest, he turned the Eiffel Tower in the tenth minute, thus gaining twenty minutes for the home stretch. But on his return he encountered an unexpected head wind, and after a terrific struggle reached the timekeepers at Saint-Cloud in the fortieth minute.
To add to the romance of this voyage, the genii of the upper elements stopped his motor, shortly after his return, and the bold sailor in his shining ship landed in a stately chestnut tree very near the house of the Princess Isabel, daughter of Dom Pedro. She very thoughtfully arranged a breakfast for him and sent it up in a basket, where he was at work disengaging the balloon, at the same time inviting him to call and relate to her the story of his voyage. A few days later she sent him a medal of St. Benedict “that protects against accidents.” He wore the medal, and on his very next trial escaped without a scratch from an appalling accident which might have terminated fatally. He continued to wear the gift of that gracious princess, on a thin gold chain circling his wrist, and many a time thereafter endured unscathed the most dreadful accidents, as if he possessed a charmed life.
On August 8, 1901, the dauntless aëronaut again sailed for the coveted prize, at the same still morning hour, sacred to duels and aërial contests. In nine minutes he turned the tower and headed bravely for home. But soon a leaky valve let the balloon shrink and the wires sag into the whirring propeller, which therefore had to be stopped. Santos-Dumont now had the choice of drifting back against the tower and destroying his vessel high in air, or of descending at once, by allowing the balloon to sink without discharge of ballast. He chose the latter course, hoping to land on the Seine embankment; but instead his balloon struck the top of the Trocadero hotel, exploded and fell in fluttering shreds into the courtyard. Some firemen who had been watching the flight from a distance, came with a rope and found the long car leaning like a ladder against the wall of the court, the balloon shreds hanging from it in graceful folds, and Captain Santos-Dumont perched aloft in his wicker basket wearily waiting for St. Benedict’s further aid. As usual, he was rescued intact.
On the evening of his fall on the roof of the hotel Santos-Dumont issued specifications for his famous No. 6, which surpassed all its predecessors in safety and speed. It had the shape of an elongated ellipsoid with pointed ends, measured 110 feet in length, 20 feet in major diameter, 22,239 cubic feet in volume, and had an absolute ascensional force of 1,518 pounds. It was driven by a twelve horse-power four-cylinder water-cooled engine which gave the propeller a thrust of 145 pounds. To insure against buckling of the gas bag, an air pump connected with the motor, kept the ballonet under constant pressure, regulated by an escape valve through which the excess of air passed outward. To secure the envelope against rupture, due to the expansion of the hydrogen at unusual elevations, a stronger valve was used to let the gas escape from the envelope into the atmosphere. Thus the air escape valve kept the pressure constant in the partially distended ballonet, and consequently also in the surrounding gas envelope itself; while the stronger gas valve in the envelope opened only in an emergency, when the gas pressure had fully collapsed the internal air pocket and was threatening to explode the envelope. With all its improvements this new vessel was finished and inflated by August 4, being a work of twenty-two days, and after some preliminary trials was ready to try for the Deutsch prize.
The day of triumph followed quickly. On October 19, 1901, at 2.45 P. M., Santos-Dumont again headed for the Eiffel Tower in presence of the official witnesses. In spite of a wind of six meters per second striking him sidewise, he held his course straight for the goal, and turned it in the ninth minute, as in his preceding attempt. On the return he had to struggle against a quartering wind and the caprice of his motor, which sometimes threatened to stop, and again spurted so actively as to turn the ship upward at a steep angle. The mighty throng below, in the Auteuil race track and the Bois de Boulogne, sent up immense applause, then suddenly held its breath in alarm, as the vessel pitched violently. But the hardy little rider was self-possessed and at home on his vaulting Pegasus. Alert to every prank he held his course straight for the timekeepers and passed over their heads at exactly twenty-nine and one-half minutes after starting.
His unmercenary disposal of the two rich awards which he had won seemed no less commendable than the dauntless industry which achieved such rapid success. The Deutsch prize amounting in all to one hundred and twenty-five thousand francs he divided into two unequal parts. The greater sum of seventy-five thousand francs he gave to the prefect of police of Paris, to be used for the deserving poor; the remainder he distributed among his employés. The Encouragement Prize of four thousand francs a year, mentioned before, he also declined to retain, but instead he founded with the money a new prize at the disposal of the Aëro Club. As a second reward for his triumphal voyage around the Eiffel Tower, he received from the Brazilian government one hundred and twenty-five thousand francs and a beautiful gold medal bearing appropriate and very complimentary inscriptions.
Now that the stimulus and excitement of striving for the Deutsch prize was over, the ardent inventor was free to develop and test his air ships in a deliberate and scientific manner. He therefore set about building specialized types of motor balloons, and practicing with them over all kinds of territory, smooth and rough. Within the next six years he constructed eight more air ships making altogether fourteen, besides his various free balloons, to say nothing of the aëroplanes and hydroplanes which he found time to develop. But before indulging in these new luxuries he would have more experience with his No. 6.
When the cold weather set in, following his victorious flight about the Eiffel Tower, Santos-Dumont went with his No. 6 to Monaco, to practice air cruising over the Mediterranean. The Prince of Monaco had erected for him an “aërodrome,” or balloon shed, facing the sea and very near shore. On pleasant days the daring pilot would cruise up and down the bay, not far from shore, trailing his guide-rope over the waves with the greatest ease, and to the applause of thousands of spectators. But on February 14, 1902, he set forth on a pleasure cruise over the bay with insufficient gas pressure, and thus came to grief. The bag grew flabby; the hydrogen poured to its higher end; the vessel reared up so steeply that the propeller had to be stopped to avoid its cutting the envelope. Rather than drift at the mercy of the wind, the pilot opened the valve and sank slowly to the water where he was rescued by a boat. On the following day the parts of his No. 6 were fished out of the sea and sent back to Paris. His few days’ practice had taught him the delights of guide-roping over the waters, and his accident induced him in future to sew unvarnished silk partitions across his balloons, to prevent the hydrogen passing too suddenly from one end to the other.
Returning to Paris he built for himself an “aërodrome,” provided with great sliding doors like the one at Monaco, and equipped with a hydrogen plant, constructive appliances, and everything needed for the rapid rebuilding or repair of air ships. It stood in a vacant lot surrounded by a high stone wall and was made of posts covered with red and white canvas, so that it looked like a great striped tent. Inside, the central stalls were 31 feet wide, 165 feet long, and 44½ feet high,[12] the whole enclosure having accommodation for seven dirigibles all inflated and ready for instant service. When completed, in the spring of 1903, it was at once used to harbor three new air ships. These were the No. 7, designed for racing contests; the No. 9, called the Runabout, a minim air ship used for calls and short pleasure trips; and the No. 10, called the Omnibus, intended for several persons, with ample supplies for a considerable journey.