Nature's teachings : human invention anticipated by nature / by J.G. Wood.

  • John George Wood
Date:
1877
Catalogue details

Licence: Public Domain Mark

Credit: Nature's teachings : human invention anticipated by nature / by J.G. Wood. Source: Wellcome Collection.

    462/564 (page 436)
    USEFUL ARTS. CHAPTER XI. AEROSTATICS.—WEIGHT OF AIE.—EXPANSION BY HEAT. Ascent and Descent.—The Balloon and the Parachute.—Description of the Balloon.—The Montgolfier Balloon.—Causes of its Abandonment.—The Gas Balloon.—Hydrogen Gas and its Manufacture.—The Gossamer Spider.— Eeasons of its Ascent and Descent.—Many Species of Gossamers.—Descrip- tion of the Parachute.—Its Mode of Action.—A Balloon converted into a Parachute.—Toy Parachutes.—Natural Parachutes.—The Dandelion Seed and its Structure.—The Flying Squirrel.—The Flying ]\Ionkey.—Flying Mice and Flying Opossums.—The Flying Dragon and its Pseudo-wings.— The Flying Frog.—Weight of Air.—Pressure per Square Inch.—The Air Ocean and its Storms.—Principle of Air-currents.—The Sun, the Earth, and the Air.—Ventilation of Mines. —Choke-damp and Fire-damp.—The Air- shafts.—Chimneys of Factories.—The Steam-blast.—The Barometer, and Mode of its Construction.—Water and Mercury.—Sucking Eggs and Sugar- cane.—Expansion of Water and Metals by Heat.—The Thermometer.— Wheel-making. Aerostatics. WE will begin this chapter with, the only two modes at present known by which man can ascend from the earth or descend to it with safety, namely, the Balloon and the Parachute, the latter being generally attached to the former, and detachable at pleasure. The Balloon is, in fact, as its name imports, a large, hollow, air-tight ball, filled with some substance lighter than ordinary air. The original Balloons by Montgolfier were filled with heated air exactly like our toy fire-balloons. Just as the supply of hot air is kept up in them by a sponge dipped in lighted spirits of wine, so in Montgolfier's balloons the same object was attained by straw which was kept continually burning in a grate. There were, however, two disadvantages about this plan. The first was the great danger of fire, which on one occasion did