THE SANTOS-DUMONT BALLOON 1901
Scientific American August 10, 1901 page 89
The balloon of M. Santos - Dumont, which made a successful trip across Paris, as recorded in the SCIENTIFIC AMERICAN for July 27, is the fifth which he has built, and we are now enabled to give some detailed views of this remarkable airship.
The balloon proper is cylindrical and is covered with silk, its extremities being pointed. It is 111 feet long, and its cubical capacity is 19,300 feet. Suspended by piano wire some 35 or 40 feet below the balloon is a light framework whose profile very much resembles that of the balloon proper. The framework is triangular in section, and is formed of
three long pieces of wood, secured at the end and strengthened by cross-bracing and steel wires.
This framework supports a four-cylinder, sixteen horse power motor of the Dion-Bouton type, the fuel reservoir, the shaft and the propeller. The engine is placed well toward one end, and the aeronaut rides in a light basket at the other end. Here he has under his control all of the machinery for maneuvering the balloon, also the ballast and the guide-ropes. The respective positions of the various weights were determined after many experiments, and its equilibrium is perfect.
This assures its horizontality and an equal tension on the suspenders. This explains why the aeronaut is so far separated from his motor. The propeller, 14 feet in diameter, is composed of two vanes of wood and steel, covered with silk and highly varnished; it attains a speed of 150 turns a minute. The steering device is of silk and is placed between the balloon and the framework above the propeller. The balloon is inflated with hydrogen, and in order to maintain at all times a tension on the envelope—that is to say, perfect inflation—a compensating balloon filled with air is placed in the interior. This is inflated automatically, as required, by a small compressor actuated by the motor, the air being conducted to it by tubing.
A guide-rope is suspended under the framework, and with its aid the necessary inclination is obtained to effect the movements of ascent and descent. Such, in brief, is the apparatus and method employed by M. Santos-Dumont. After his slight mishap on the day of his remarkable trip on the 13th of July, M. Santos-Dumont repaired the damage, and on July 29 he made another ascent.
He had arranged to make his promised trip over Paris in the afternoon, but was obliged to abandon the idea, as he found that the motor was working badly. In order, however, not to disappoint the numerous visitors to St. Cloud, he gave a maneuvering exhibition over the Bois de Boulogne. Several ascents were made, and the guide-rope frequently caught in the trees, but it was re-leased without any harm being done. The visitors were all astonished at the marvelous control the inventor had over the balloon. The motor is still giving him trouble, and on his last trip the screw was frequently at a standstill. The balloon's great size and the absence of landing platforms help to make the ascents and descents difficult. For our engravings we are indebted to L'Illustration.