The Ville de Paris showed considerable resemblance to her prototype, the France of 1884, but differed from that elegant vessel in various important features. Her hull was shaped like a wine bottle with its thickest end, or bow, brought to a sharp projectile point, and its other end furnished, like an arrow, with four fixed guiding surfaces to steady its flight. These guiding surfaces were elongated, finlike, cylindrical sacs, inflated as shown in the illustration. The hull measured 200 feet long, 34½ feet in major diameter, 112,847 cubic feet in volume. Heavy bands of canvas with their edges sewed along the sides of the balloon served as flaps for the attachment of the cords suspending the long car beneath. With this long suspension the weight of the car was more evenly distributed over the envelope than in the Lebaudy balloons. An interesting improvement in this air ship was the stabilizing planes, placed above the car, fore and aft, to lift or depress aëroplanelike, thus enabling the pilot to raise or lower the vessel, also to alter her trim, or to check her pitching. As might be expected, her flight was very steady, but as the motor developed only 70 to 75 horse power, her velocity did not exceed twenty-five miles per hour. In January, 1908, she made a run of 147 miles in seven hours, six minutes, with an average speed of 21 miles an hour. Further details of construction are given in [Appendix III].
We now have had examples of the three leading types of motor balloons; the rigid, the semirigid, the flexible. The rigid type, as exemplified in the Schwartz and Zeppelin air ships, is characterized by its solidly trussed hull of invariable size and form to which all other parts are directly attached. The semirigid type, exemplified in the Lebaudy vessels, has a flexible hull, generally of woven fabric, with a trussed floor or platform for its ventral part, from which the car is suspended. The flexible type, as seen in the Ville de Paris, the France, and its predecessors, consists of a flexible hull entirely devoid of stiffening framework, together with a car, usually quite long, suspended from the bag directly. These are all of the important kinds in use at present. A combination of balloon and aëroplane has been tried by Santos-Dumont, Malecot, and others, but thus far has not resulted in a very successful and distinct type. Of the many powerful, swift, and elegant balloons which sprang into being after the success of the Lebaudy vessels, all could be classified under the above three types. Neither kind proved preëminently the fittest for all service, but the semi-rigid and flexible balloons multiplied most rapidly; partly, no doubt, because of their cheapness and convenience of management. We may review briefly this new crop of air ships, before turning to the novel and huge rigid vessels of Count von Zeppelin.
The Ville de Paris was followed, in 1909, by the Clément-Bayard, a slightly larger vessel of very similar pattern, constructed for the Russian government for $40,000. It also, like the Ville de Paris, was built by the Astra Society. The most striking feature of this new balloon was its curious stern with its bulblike steadying surfaces. These fin surfaces were not flat, as in the Patrie, nor cylindrical, as in the Ville de Paris, but of pear form, with the blunt ends pointing rearward and inflated like the rest of the hull. Apparently these tail bags were not economical of power, since, as is well known, a pear shape encounters greater resistance when moving sharp end forward than when moving blunt end forward. However this be, the stabilizing force proved very effective. The vessel was driven by a Clément-Bayard motor of 100 horse power actuating a wooden screw placed in front of the long car, as in the France. A speed of 30 miles an hour was attainable, and the ship could accommodate eight passengers. On one occasion it made a round trip from Sartrouville, traversing 125 miles at an average speed of 27 miles an hour. It was acquired by the Russian government on August 23, 1909, having on that day completed its third official test, and satisfied the requirement of rising 1,550 meters and voyaging two hours at a height of 1,200 meters. Two notable incidents of that voyage were that the air ship made a new record for altitude, and on landing was caught by a squall which tore it from the hands of thirty men, after which, owing to motor failure, it drifted freely across country, tripped on a willow, and fell into the Seine, whence it was rescued after considerable pains and labor.
Other vessels presently built by the Astra Society may be listed, together with their size in cubic meters, as follows: Ville de Bordeaux, 3,300 m3;[13] Ville de Nancy, 3,300 m3; Colonel Renard, 4,000 m3; España, 4,000 m3; Clément-Bayard II, 6,500 m3; Transaerienne I, 6,500 m3; Flandre, 6,500 m3 (228,579 cubic feet). These were among the most noted air ships produced in France toward the close of the first decade of the twentieth century. On the whole they proved to be swift and stable ships adapted either for military use, or for exhibitions and sport, and even for regular transportation of passengers.
The Ville de Nancy was one of the conspicuous dirigibles of the summer of 1909. It was constructed primarily for use at the Exposition at Nancy, and was owned by the Compagnie Générale Transaerienne, an aërial passenger transportation society organized at Paris, in March, 1909, with a capital of one million francs. This society planned to inaugurate an aërial line from Paris to Bordeaux, in 1910, equipped with other vessels of the Astra construction, more powerful than the Ville de Nancy, and capable of transporting a dozen passengers.
PLATE IV.
LA VILLE DE PARIS.
Photo E. Levick, N. Y.