66 HISTORY OF AEROSTATION. 



to the ingenious Dr. Black, of Edinburgh, that if a bladder, suffi- 

 ciently light and thin, were filled with this air, it would form a muss 

 lighter than the same bulk of atmospheric air, and rise in it. This 

 thought was suggested in his lectures in 1707 or 1768 ; and he pro. 

 posed, by means of the allantois of a calf, to try the experiment. 

 Other employments, however, prevented the execution of his d',itn. 

 The possibility of constructing a vessel, which, when filled with in. 

 flammable air, would ascend in the atmosphere, had occurred also to 

 Mr. Cavallo about the same time ; and to him belongs the honour 

 of having first made experiments on this subject, in the beginning <>t 

 the year 1782, of which an account was read to the Royal Society, 

 on the 20th of June, in that year. He tried bladders; but the thin, 

 nest of these, however scraped and cleaned, were too heavy. In 

 using China-paper, he found that the inflammable air passed through 

 its pores, like water through a sieve ; and having failed of success 

 by blowing this air into a thick solution of gum, thick varnishes, 

 and oil paint, he was under a necessity of being satisfied with soap, 

 balls ; which, being inflated with inflammable air, by dipping the 

 end of a small glass tube, connected with a bladder containing the 

 air, into a thick solution of soap, and gently compressing the blad- 

 der, ascended rapidly in the atmosphere ; and these were the first 

 sort of inflammable air-ballons that were ever made. 



But while aerostation seemed thus on the point of being made 

 known in Britain, it was all at once announced in France, by two 

 brothers, Stephen and John Moutgolfier, natives of Annonay, and 

 masters of a considerable paper-manufactory there, who had turned 

 tbeir thoughts to this project as early as the middle of the year 1/82. 

 Their idea was to form an artificial cloud, by inclosing smoke in a 

 bag, and making it carry up the covering along with it. In that 

 year, the experiment was made at Avignon with a fine silk bag ; and 

 by applying a burning paper to an aperture at the bottom, the air 

 was rarefied, and the bag ascended to the height of 70 feet. Va- 

 rious experiments were now tried upon a large scale, which excited 

 the public curiosity very greatly. An immense bag of linen, lined 

 with paper, and containing upwards of 23,000 cubic feet, was found 

 to have a power of lifting about 500 pounds, including its own 

 weight. Burning chopped straw and wool under the aperture of the 

 machine, immediately occasioned it to swell, and afterwards to 

 ascend into the atmosphere. In ten minutes it had risen 6000 feet: 

 and when its force was exhausted, it fell to the ground at the dis- 



