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BISTORT of the SOCIET'K s 



From 10 (28th) to 4 A. M. fell 1 /. T h 



. From 4 to 1 o A. M. rofe 1 -/ 



>ept * ) From 10 A. M. to 4 P. M. fell 1 T »- 



From 4 to 10 P. M. rofe 1 



The obfervations on the 30th were to the fame effecl ; and 

 hence it is concluded that at the equator the flux and reflux of 

 the atmofphere produces in the barometer a variation of about 

 1 line -V Englifh, correfponding, as M. Lam an on remarks, to 

 a height in the atmofphere of nearly 1 00 feet. According to 

 Bernouilli, the action of the fun and moon- mould produce a 

 tide of about 7 feet, and according to Mr de la Place, a tide 

 not nearly fo great. 



It mould be obferved, that when thefe obfervations were 

 made, the moon was in her laft quarter, and the fun a few de- 

 grees to the fouth of the equator. '-^.The latitude on the 28th 

 was 5c/ north, and 1 1' north on the 29th;; in the night between 

 that and the 30th, the fhip crofted the line ; and on the 30th 

 at noon, the latitude was 42' fouth : the longitude all this while 

 between 17 ° 31' and 18 33' weft of Paris, by the time-keeper ; 

 fo that the coafl of Africa, which was the neareft land, was di- 

 stant about 8° of a great circle, and the American continent 

 about 1 9 . ■ 



The agreement between thefe, and DrBALFOu r's obfervations 

 at Calcutta is very remarkable. Dr Balfour found that du- 

 ring the whole lunation, in which he obferved the barometer 

 from half-hour to half-hour, the mercury constantly fell from 

 10 at night to 6 in the morning; from 6 to 10 in the mor- 

 ning it rofe ; from 10 in the morning to 6 at night it fell again ; 

 and laftly, rofe from 6 to 10 at night. The maximum height is 

 therefore at 10 at night and 10 in the morning, and the mini- 

 mum at 6 at night and 6 in the morning. The only difference 

 is, that in Mr Lamanon's obfervations, the minimum is ilated 

 to have happened about 4, inftead of 6. This, however, will 



not 



