ALBERTO SANTOS-DUMONT
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the suspension-cords of my basket directly, by means of small wooden rods introduced into horizontal hems, sewed on both sides along the stuff of the balloon for a great part of its length. Again, in order not to pass the 66 pounds weight, including varnish, I was obliged to choose Japan silk that was extremely fine but fairly resisting. Up to this time no one had ever thought of using this for balloons intended to carry up an aëronaut, but only for little balloons carrying light registering apparatus for investigations in the upper air.
I gave the order for this balloon to M. Lachambre. At first he refused to take it, saying that such a thing had never been made, and that he would not be responsible for my rashness. I answered that I would not change a thing in the plan of the balloon, if I had to sew it with my own hands. At last he agreed to sew and varnish the balloon as I desired. On my part I changed my petroleum motor from my tricycle to my basket, behind which it was to work an aluminium screw propeller with two arms, each 1 meter (3.3 feet) across.
I made daily trials; and they greatly encouraged me. Suspending the basket, with its motor and propeller, by a cord from the rafters of the workshop, I was able to try the traction-power of motor and propeller au point fixe, as they say. Once the machinery was started, the tendency of the propeller was to carry the whole basket system violently forward, like the forward movement of a pendulum. This I held back by a horizontal rope attached to a dynamometer. So measured, the traction-power of the motor and propeller showed itself to be as high as 25 pounds-a figure promising good speed for a cylindrical balloon of my dimensions, whose length was equal to seven times its diameter. With 1,600 turns to the minute, the propeller, which was directly attached to the motor-shaft, might easily, if all went well, give the air-ship a speed of not less than 8 meters (26 feet) a second.
At the same time I made a rudder of silk stretched over a triangular frame, and an arrangement of shifting weights which, by means of cords, could be shifted from the stem to the stern of the air-ship, so as to incline its axis suitably with relation to the horizontal line, for either ascending, descending, or remaining in equilibrium. All this occupied several months. The work was all carried on in the little workshop of the Rue du Colisée, only a few steps from the place where later on the Aéro Club was to have its offices.
In the middle of September I was ready to begin in the open air. The rumor had spread among the aëronauts of Paris, who a year later were to form the nucleus of the Aëro Club, that I was going to carry up a petroleum motor in my basket. They were quite sincerely disquieted by what they called my temerity; and some of them made friendly efforts to show me the permanent danger of such a motor under a balloon filled with a highly inflammable gas. They begged me, instead, to use the electric motor, which is infinitely less dangerous.
Meanwhile, I hastened my preparations for inflating my balloon at the Jardin d’ Acclimatation, where a captive balloon of heavy weight was already installed and furnished with everything needful daily. This gave me facilities for obtaining, at 1 franc (20 cents) per cubic meter (about 35 cubic feet), the 180 cubic meters (6,355 cubic feet) of hydrogen which I needed.
On the 18th of September my first air-ship—the ‘‘Santos-Dumont No. 1’’ as it has since been called, to distinguish it from those which followed—lay stretched out on the turf amid the trees of the beautiful park-like Jardin d’Acclimatation, the new Zoological Garden of the west of Paris. To understand what followed I must explain the starting of spherical balloons from such places, where groups of trees and other obstructions surround the open space. When the weighing and balancing of the balloon are finished and the aëronauts have taken their place in the basket, the balloon is ready to quit the ground with a certain ascensional force. Thereupon aids carry it toward an extremity of the open space in the direction from which the wind happens to be blowing; and it is there that the order ‘‘Let go all!’’ is given. In this way the balloon has the entire open space to cross before reaching the trees or other obstructions which may be opposite, and toward which the wind would naturally carry the balloon. So it has time to rise high enough to pass over them. Moreover, the ascensional force of the balloon is regulated accordingly: it is very little if the wind be light; while it is more if the wind be stronger. I had thought that my air-ship would be able to go against the wind that was then blowing; therefore I had intended to place it for the start at precisely the other end of the open space from that which I have described—i.e., down-stream, and pointed up-stream against the air-current with relation to the open space surrounded by trees. I would thus move out of the open space without difficulty, having the wind against me: for, under such conditions, the relative speed of the air-ship
