“I made other successful trips in the ‘Santos-Dumont No. 3,’ the last time losing my rudder and landing, luckily, on the plain at Ivry. I did not repair it. The balloon was too jumsy and the motor was too weak. I now had my own ‘stable’ and gas-plant; and, anxious to profit by past experience, I gave Lachambre the order for my No. 4.”
“That was the air-ship of the Exposition year and the International Congress of Aëronauts, was it not?”
“Yes, the one with the bicycle-saddle.”
This is also the model with which the foreign public has been made most familiar, because most of the newspapers came out with old cuts and photographs of it during M. Santos-Dumont’s sensational trips, with a quite different keel, in July, 1901. In No. 4 the thirty-foot bamboo pole became part of a real keel, no longer hanging above the navigator’s head, but amplified by vertical and horizontal cross-pieces and a system of tightly stretched cords. It sustained motor, petroleum-reservoir, propeller, and navigator in a spider-web frame without a basket. It was a daring innovation. The navigator himself must sit on a simple bicycle-saddle in the midst of the spider-web, where the absence of the traditional balloon-basket seemed to leave him astride a pole in the midst of a confusion of ropes, tubes, and machinery.
It was more than a bicycle-saddle, however; it was a whole bicycle-frame, around which the inventor had united cords and other means for the controlling of the shifting-weights, the striking of the motor’s electric spark, the opening and shutting of the balloon’s valves, the turning of the water-ballast’s spigots, and all the other functions of the air-ship. The rudder, for example, was controlled by the handle-bars; and the propeller was started, as in a petroleum tricycle, by working the pedals. Even the bicycle’s wheels were put to use for moving the air-ship about on the ground. They were, of course, detachable,
“My balloon No. 4,” the inventor went on to explain, “was, both in form and capacity, a compromise between No, 3 and its predecessors. With a gas-capacity of fourteen thousand eight hundred cubic feet, it was ninety-five feet long and nine feet in its greatest diameter, but no longer a cylinder terminated by two cones. It was, rather, elliptical in form, and while not a return to the slender straightness of No. 1, it had so little of No, 3's podgy compactness that I thought it prudent to put the compensating air-balloon inside it again, this time fed by a rotary ventilator of aluminium. Being smaller than No. 3, it would have less lifting-power; but this I made up by going back to hydrogen gas.
“A new seven horse-power two-cylinder motor, made for me by Bonchet, turned the propeller at the rate of one hundred revolutions per minute, furnishing a traction effort of sixty-six pounds. It made a great improvement in my speed, and for two weeks during the summer of 1900 I enjoyed, almost daily, what seemed to me then ideal trips. On September 19 I made a kind of official trial in presence of the International Congress of Aëronauts, and received the felicitations of its members, among whom came later Professor Langley of the Smithsonian Institution.
“By this time I felt that I had gained enough experience to justify materially increasing my motive power, and a new type of sixteen horse-power motor with refroidissement à ailettes(i.e., without water-jacket) having just been created, I set about adapting it to the airship. It had four cylinders instead of two. This increased the weight to be lifted to such an extent that I must either construct a new balloon or enlarge the old one. I tried the latter course. Cutting the balloon in half, I had a piece put in, as you put a new leaf in an extension-table; and the length was thus brought to one hundred and nine feet. I then found that my balloon-shed was too short by ten feet.
“In prevision of a ‘Santos-Dumont No. 5,’ I added thirteen feet to the shed. Motor, balloon, and shed were transformed in fifteen days. It was wasted pains, for no sooner had I got the enlarged balloon filled with hydrogen than the autumn rains set in. After two weeks of the worst possible weather, I let out the hydrogen and began experimenting with the motor and propeller from a fixed point. This was not lost time; for bringing the speed up to one hundred and forty turns per minute, I realized one hundred and twenty-one pounds of traction. In truth, the motor turned the propeller with such force that I contracted pneumonia in the current of air, and found myself laid up for the winter.”
“Then you went to Monte Carlo?”
“Yes. I cured myself automobiling in the mistral. At the same time I found a broad-minded carpenter at Nice who, for a consideration, allowed me to work out a new idea in his atelier. The idea took the form of my present keel, a long triangular-sec-
