by Means of two Altitudes of the Sun. 
103 
Log. of r= 8,6178915 
— 5 = 10,1427296 
— 7= 9>996 i !39 
— 5 .7=5 20,1388455 
r m- 
18,4790480 
sy 
9*23952-fO 
sy 
Log. cosine = 9 ’ 9933S 6 ° 
2 X log. cos. = 19,9867120 
Const, log. = 3,1015 
Log. s = 10,14272 96 
— gc .= 3,2309416 
— gb = 4,34 l ° l88 
Difference = 1,1100772, producing in tab. 2d. 12' 52 " 
But there is no occasion to write down the logs, of r, s, and 7, 
again : we may add together the logs, of s and 7, and subtract 
their sum from the log. of rm 3 at the same time, as they stand 
in the former operation, and this will render the latter process 
extremely short. Let us resume the preceding example, and 
compute the area gb by the second method, and the area gc 
Lat. corrected — 54 0 27' 52" 
by the formula m 1 — dJUL 
J Sy 
