THERMOMETRICAL OBSERVATIONS. 189 



b 



2?d. . By a lunar obfervation, the ]) froml , 



the©. I 6 4 41 



do. the > from Aldebaran. 656 



Feb. 9th, . By an emerfion of the 2d fatellite 652 



1 6th. . By an immerfion of the 3d do. 5 59 25 



do. by de Lambre's Tables 6 3 26 



The longitude of Natchez is ftated in the 4th volume of the Tranfac- 

 tions of the American Philofophical Society, page 451, at 16" 15' 46' 

 weft from Philadelphia, or 91" 29' 16" which is equal to 6'' 5' 57" weft 

 from Greenwich. — That determination includes all the foregoing obferva- 

 tions previous to the loth of January, except the immerfion, and emerfion 

 of the 3d fatellite* on the 4th of that month, which from die imperfediion 

 of the theory were omitted. 



Vol. V. C c Refult 



* I have lately been fumillied by Jofe Joaquin de Ferrer, an ingenious 



Spanifli gentleman, with a number of valuable aftrcnomical obfervations, 



which he has made at different places on tliis continent : among them there 



are tliree on the eclipfes of Jupiter's fatellites made at la Guair;i, which 



correfpond with an equal number of mine made at Natchez. — They are 



the following : ^ _. 



" Apparent Time. 



'^ • C Emerfion of tlie 3d fatellite of 1( obferv-') 

 Jan. 4th. < ed by Mr. de Ferrer at la Guaira J ^ ^ 



l_ Obferved at Natchez . . . 8 5 1 5 1 



C Emerfion of the 2d fatellite of 1^ obferv-l 

 8th. < ed by Mr. de Ferrer at la Guaira \ 

 (.Obferved at Natchez 



Difference of meridians . , . i 38 



r Emerfion 



do. 8th. \ ed by 



{_ Obferve 



Difference of meridians . . . 1 3S 13 



f Emerfion of the i ft fatellite of 11 obferv- 1 

 do. 91I1. < ed by Mr. de Ferrer at la Guaira ' J 

 (. Obferved at Natchez 



Difference of meridians . . . 1389 



Mean . . . . • . i 38 7.3 



The telefcopes ufed by Mr. de Ferrer and myfelf were both acromatic, 

 and nearly of the f/ime magnifying power, (that is about 1 20), the difference 

 of the meridians will therefore require no correction on account of the dif- 

 ference of the inftruments, and may be fafely taken as above ftated : by 

 which it appears that the town of N.itchez, is i'" 38' 7". 3 or 24° 31' 49* 

 weft of la Guaira. — The latitude of la Guaira as determined by Mr. de 

 Ferrer is 10° 36' 40'' N. 



