GA Y-LUSSAC. 311 



doubtless said to Alexander, in August, 1804, " He is 

 now translating Agamemnon." 



The fact of William's being hard at work on his be- 

 loved iEschylus, and that Frau Caroline intended to re- 

 main in Paris until the commencement of the following 

 year, determined Alexander to remain there until he had 

 regulated his collections and arranged his journals for 

 publication. He renewed his intimacy with his former 

 scientific associates, especially with his friend, Gay-Lus- 

 sac, who had just distinguished himself as an ajronaut, 

 by making two ascensions from the Conservatory of Arts, 

 one with M. Biot, on the 24th of August, and one alone, 

 on the 15th of September. The object of these ascen- 

 sions was to examine whether the magnetic power ex- 

 perienced any appreciable diminution as we leave the sur- 

 face of the earth. Saussure, who made experiments on 

 the Col du Geant, at eleven thousand feet above the level 

 of the sea, thought he could perceive a very sensible de- 

 crease of magnetic virtue : some aeronauts even asserted 

 that it vanished at a certain height. Loaded with a cargo 

 of galvanic apparatus, barometers, thermometers, hygro- 

 meters, and electrometers, besides a small menagery of 

 frogs, insects, and birds, Biot and Gay-Lussac rose from the 

 Conservatory amid the plaudits of all Paris. The lower 

 side of the clouds through which they passed had a bluish 

 tint, similar to that which they exhibit on the surface of the 

 earth, but as they rose above them, they saw that they 

 were full of small eminences and undulations, like a vast 

 field of snow ploughed and drifted by the wind. They 

 commenced their experiments at the height of six thou- 

 sand five hundred feet, and continued them to the height 

 of fifteen thousand seven hundred feet, and the result of 



