P.S. Tuesday Evening ... I hear farther that the Travellers had perfect Command of the Carriage, descending as they pleas’d by letting some of the inflammable Air escape, and rising again by discharging some Sand; that they descended over a Field so low as to talk with Labourers in passing and mounted again to pass a Hill. The little Balloon falling at Vincennes shows that mounting higher it met with a Current of Air in a contrary Direction; an Observation that may be of use to future aërial Voyagers.
B. Franklin.
APPENDIX III
France
The Clément-Bayard II[80]
The Clément-Bayard II may be classed among the airships usually called “flexible.” The shape of its hull is preserved not by any rigid framing, but by internal gas pressure maintained by ballonets fed by ventilating fans. Moreover, the suspension which binds envelope and car together as one solid is composed wholly of flexible elements, without any rigid intermediary structure.
The general plan, then, of the craft comprises three prominent features, well marked and distinct in character:
(a) The fish-shaped envelope with major section well forward, a form favorable to both speed and stability.
(b) The trussed girderlike car whose length allows the load to be distributed over the hull, thus preserving its nicety of outline. The most minute and technical and mechanical details were studied for eighteen months by M. Clément and his devoted collaborator, the engineer Sabathier. The girder car, as will be seen presently, is particularly well designed to serve as car, sustainer and stiffener. No stabilizing device is attached to the envelope; all are fixed to the car, on which is mounted also the complete propulsion plant.