689 



fluence on fevers than the physicians of Jamai- 

 ca, had the patience to observe the barometer 

 at Calcutta in 1794, during a whole lunar revo- 

 lution, every half hour. 



I began, with M. Bonpland, the series of my 

 observations on the variations of the weight of 

 the atmosphere, July 1 8th, 1799, two days after 

 our arrival atCumana,and continued them care- 

 fully during five years, from the 12° of south la- 

 titude to the 23° of north latitude, in plains, and 

 on table-lands of the same height as the peak of 

 TenerifFe. Since the period of my voyage to the 

 equator, this phenomenon has occupied the at- 

 tention of almost all the travellers and naturalists 

 furnished with instruments fitted to make accu- 

 rate observations. I shall confine myself to the 

 mention of the observations of M. Horsburgh * 

 during his stay on the coasts of China and 

 India; of Captain Kater, in the high plains 

 of Mysore ; of M. Ramond, in Auvergne ; of 

 MM. Langsdorf and Horner who in Krusen- 

 stern's Voyage, united more than 1400 ba- 

 rometric heights ; of M. d'Eschwege, in the 

 missions of the Coroatos Indians, and on the 

 table-land that surrounds the presidio of S. 



* See the letter of this learned navigator, to Henry Ca- 

 vendish, in the Pliil. Trans., 1805, p. 178, and in Nicholson's 

 Journ., 1806, Vol. xiii, No. 50, p. 16 and 56. 



f Mem. de V Acad, de Peiersbonrg, 1809, Tom. i, p* 45Q> 

 486. 



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