THERMOMETRICAL OBSERVATIONS. i-i 



deducft 6' 15'' the equation of time, and the remainder 2'' 47' 1" will be 

 the apparent time of the cbfervation. The obfei-ved dillance correftcd for 

 parallax refraiflion, &c. will anfwer to about S"" 42' 22" at Greenwich, by 

 which the difference of meridians appears to be about 5'' 55' 21". 



By fuppcfmg the obfervation on the 3d fatellite of 2/, with the lunar ob- 

 fervation to be equivalent to either of llio.'e en the ift fatsliite, the mean 

 longitude will be had as belov.'. 



Longitude by the 3d fatellite 

 do. by the lunar obfervation 



-» Mean 



do. by the ift fatellite en the'} 



2ift of December J 



do. by do. on the 2Sth of) 



December j 



Mean . . ' 5 55 ^z.S = 88° 50' 



h / t 



42' weft from Greenwich, or o 54 47 8 = 13° 41 57" weft from the 

 city of Philadelphia. 



The foregoing obfervations were maJe under veiy un- 

 favourable chcumftances, the weather intenfcly cold, and 

 not a fufficient number of tents to fecure our inftruments, 

 and cover our men : our ftore-boat having been left be- 

 hind, and was frozen up near the mouth of the Wabafh 

 river till about the 20th of January. The fpirits in the 

 veffel in which the plummet of the fedor was fufpended 

 were frequently congealed, and what appeared fomewhat 

 fmgular, was that the fpirits began to freeze on the out- 

 fide of the veflel very near to the upper edge, from which 

 it extended in prongs, like bucks-horns, and did not con- 

 geal within till the fpirits fell about -^ of an inch below 

 the upper edge. — The vefTel was i|- inches in diame- 

 ter. — The ice on the outfide did not appear to contain 

 a full proportion of fpirit. Although the obfervations 

 were made under unfavourable circumftances, I have no 

 reafon to fuppofe them liable to any material objedion, 

 and therefore prefume that the determinations of the la- 

 titude, and longitude, of the confluence of the two rivers 

 are fufficiently correct for geographical purpofes, notwith- 



ftanding 



