Aerostation. 291 



landed the cat, which was almost dead with cold ; then rising, he 

 prosecuted his voyage. He ascribes his descent to the action of 

 an oar ; but as he was under the necessity of throwing out ballast 

 in order to reascend, his descent was more probably occasioned 

 by the loss of inflammable air. At ten minutes past four he de- 

 scended on a meadow, near Ware, in Hertfordshire. The only 

 philosophical instrument which he carried with him was a ther- 

 mometer, which in the course of his voyage stood as low as 29°, 

 and he observed that the drops of water which collected round 

 the balloon were frozen. 



The largest and the most interesting voyage, which was per- 

 formed about this time, was that of Messrs. Roberts and Mr. 

 Collin. Hullin, at Paris, on the 19th of September, 1784. 

 Their aerostat was filled with inflammable air. Its diameter was 

 twenty-seven feet and three-quarters, and its length was forty-six 

 feet and three-quarters, and it was made to float with its longest 

 part parallel to the horizon, with a boat nearly seventeen feet long 

 attached to a net that went over it as far as its middle. To the 

 boat were annexed wings, or oars, in the form of an umbrella. 

 At twelve o'clock they ascended, with four hundred and fifty 

 pounds of ballast, and after various manoeuvres descended at for- 

 ty minutes past six o'clock near Arras,, in Artois, having still two 

 hundred pounds of their ballast remaining in the boat. Having 

 risen about one thousand four hundred feet, they perceived stormy 

 clouds, which they endeavored to avoid, but the current of air 

 was uniform from the height of six hundred to four thousand 

 two hundred feet. The barometer on the coast of the sea was 

 29-61 inches, and sunk to 23-94 inches. They found that by 

 working with their oars they accelerated their course. In the 

 prosecution of their voyage, which was one hundred and fifty 

 miles, they heard two claps of thunder ; and the cold occasioned 

 by the approach of stormy clouds made the thermometer fall from 

 seventy-seven degrees to fifty-nine degrees, and condensed the 

 .inflammable air in the balloon, so as to make it descend very low. 

 From some experiments, they concluded that they were able by 

 the use of two oars to deviate from the direction of the wind about 

 twenty-two degrees. But this experiment requires repetition, in 

 order to ascertain with accuracy the effect here ascribed to oars. 



The second aerial voyage in England was performed by Mr. 

 Blanchard and Mr. Shelton, professor of anatomy to the Royal 

 ♦ Academy, the first EngJishmen who ascended with an aerostatic 

 machine. This experiment was performed at Chelsea on the 16th 

 of October, 1784. The wings used on this occasion seemed to 

 have produced no deviation in the machine's track from the di- 



