29. *9erostat{on. 



the parachute. Al first, viz., before the parachute opened, he 

 fell with great velocity ; but as soon as the parachute was expand- 

 ed, which took place a few moments after, the descent became 

 very gentle and gradual. A remarkable circumstance was ob- 

 served ; namely, that the parachute, with the appendage of cords 

 and basket soon began to vibrate like the pendulum of a clock, 

 and the vibrations were so great, that more than once the para- 

 chute, and the basket with Mr. Garnerin, seemed to be on the 

 same level, or quite horizontal : however, the extent of the vi- 

 brations diminished as he descended. On coming to the earth, 

 Mr. Garnerin experienced some pretty strong shocks ; but he 

 soon recovered his spirits, and remained without any material 

 hurt. As soon as the parachute was separated from the balloon, 

 the latter ascended with great rapidity, and, being of an oval form, 

 turned itself with its longer axis into an horizontal position. 



The air balloon is an hydrostatic machine that consists of a bag 

 filled with air, so light, that the whole is specifically lighter than 

 the common air of the atmosphere. Fig. 2. Plate X. It is, in fact, 

 a vessel filled with a fluid which will float in another fluid — air in 

 air. There are two kinds of balloons ; those raised with rarefied, 

 and those filled with inflammable air. And the best forms for 

 balloons are of a globe, and an egg-like figure. Large balloons, 

 for inflammable air, must be made of silk, and varnished over, so 

 as to be air tight. The car, or boat of a balloon, is made of 

 wicker work covered with leather, and well varnished, or painted, 

 and is suspended by ropes proceeding from the net which goes 

 over the balloon. The inflammable air for fiUing the balloon is 

 procured by putting a quantity of iron filings, or turnings, with 

 some oil of vitriol diluted with water, into casks lined with lead. 

 From the top of these casks tin tubes proceed, which unite into 

 one that is connected with the silk tube of the balloon. As rep- 

 resented by Fig. 1. Plate X. Balloons cannot be made smaller 

 than five or six feet in diameter, of oiled silk, as the weight of 

 the material is too great for the air to buoy it up. .They may be 

 made smaller of thin stripes of bladder or other membrane, glued 

 together. 



The first principles of the science of aerostation have been long 

 and generally known, though the application of them to practice 

 seems to be altogether a modem discovery. The invention of 

 balloons, though far-famed and brilHant, cannot be considered as 

 having hitherto added much to the comfort or utility of man. The 

 only practical purposes which it has been made to subserve, are 

 those of aiding in meteorological inquiries, and inspecting the 

 lortificaiions and reconnoitring the camp of an enemy, which could 



