Hydrostatics and pneumatics / [Dionysius Lardner].

  • Dionysius Lardner
Date:
1831
Catalogue details

Licence: Public Domain Mark

Credit: Hydrostatics and pneumatics / [Dionysius Lardner]. Source: Wellcome Collection.

    359/376 (page 343)
    chute to descend with a uniform velocity. This velo- city will be small in the same proportion as the parachute is large, and as the weight of the car and its contents is small. As the gas by which a balloon is inflated is lighter than the atmosphere, the valve provided for its escape, when the aeronaut wishes to descend, is placed usually in the top of the balloon. If it were placed in the bottom, even although it were open, the gas would not escape; at least not in any considerable quantity, nor with any degree of certainty. The superior pressure of the atmosphere, and the natural levity of the gas itself, would prevent its es- cape ; but when the valve is placed in the top, the gas will issue from it on the same principle as a lighter fluid rises in a heavier. The car which bears the aeronaut is usually Fig. 48. supported by a net-work which extends over the balloon.