715 



The regularity of the variations marked in 

 the preceding table, are found in more than a 

 thousand heights, which I carefully examined 

 on the registers of the Abbe Richenet. During 

 the course of the whole year 1814, the centi- 

 grade thermometer descended at Macao in Ja- 

 nuary, to 5° below the freezing point; it rose 

 at the end of August, to 30*4°. There were 

 frequent tempests, and thirty-six stormy days ; 

 more than 2.316 of rain water fell, and amidst 

 so many climateric changes, I did not remark 

 one single period of seventeen hours during 

 which the ascending and descending movements 

 of the barometer (from 5 h in the morning to 10 h , 

 from 10 h to 5 h in the afternoon, and from 5 h till 

 10 h in the evening) had been intervened. 



On the east of Macao, in the South Sea, MM. 

 de Langsdorf, Horner, and Simonoff found, by 

 a mean drawn from 5700 horary observations, 

 the limiUhours nearly the same, namely : M. 

 de Langsdorf, taking the mean for the north 

 and south torrid zone + 9 h 40' in the morning ; 



— 3 h 55' afternoon ; + 10j h in the evening; 



— 3£ h after midnight : M. Simonoff, in taking the 

 mean for the space contained between the pa- 

 rallels of 10° and 30° south latitude : + 9 h 24' 

 in the morning; — 3 h 24' in the afternoon; 

 + 9 h 30' in the evening ; and — 3 h 18' after 

 midnight. The Russian astronomer made ob- 

 servations in the equinoxial region of the At- 



