THERMOMETRICAL OBSERVATIONS. 301 



paflable : the mean 2' 29" was therefore taken for the difference of lonari- 

 tude, which added to 5'' 26' 34." the longitude of Point Peter will give 

 5'' 29' 3" for the longitude of the obfervatory at A. — The difference of 

 latitude between A, and the mound B, has been fhewn to be 4403.2 per- 

 ches, and the difference of longitude 886.4 perches weft : thence to the 

 end of die line fuppofed to be drav\Ti N. 45 E. 640 perches from the 

 mound B, the difference of latitude will be 452.5 perches; which added 

 to the difference of latitude between A, and B, will give 4855.7 perches, 

 or 13' 8".5 nearly, which added to 30° 21' 39''. 5 the latitude of A, will 

 give 30° 34' 48" for the latitude of the termination of the line fuppofed 

 to be drawn from B. — From the obfervatory at A, to the mound B, the 

 difference of longitude by meafurement has been ftated at 886.4 perches 

 weft, from thence to the termination of the line fuppofed to be drawn from 

 B, the difference of longitude is 452.5 perches eaft, which deduifled from 

 the wefting, will leave 433.9 perches weft, which is equal to about 6" in 

 time, and when added to 5'' 29' 3" the longitude at A will give 5'' 29' 9" 

 for the longitude of the termination of the line fuppofed to be drawn as 

 above ; which dedudled from the longitude of tlie mouth of Flint river, 

 will leave 10' 24" for tlie difference of longitude between the points. 



There 



are now civen 



Tlie latitude of die mouth of Fhnt river = . . 30" 42' 42". 8 



Tlie latitude of the termination of the line fuppofed \ _ „ 



to be drawn from B | - 3° 3+ 4« 



The difference of longitude between the mouth") 



of Flint river, and the termination of the line J- = o'' 10' 24" = 2° 36' 

 fuppofed to be diawn from B J 



To find the courfe, and diftance between the given points, that is, be- 

 tween the mouth of Flint river, and the termination of the Tne fuppofed 

 to be drawn from B, which is done as follows : 



In tlie fpherical triangle DEF, let DE reprefent the co. latitude of the 

 mouth of Flint river = 59° 17' 17". 2. FE the co. latitude of the termi- 

 nation of the line fuppofed to be drawn from B = 59'^ 25' 12'', and the 

 included angle DEF 2*^ 36', being the difference of longitude between the 

 given points. 



Vol. V. R r For 



