PHYSICAL AND LITERARY. 131 



The log. of ^y°. 2957795, &c. is 1.758 1226 

 The log. of SM is 4.2032241 



The fum is 5.9613467 



The log. of CA is' 5.0000000 



The difference 0.9613467 



is the log. of 9° S'.905998, the number of 

 degrees and minutes in an angle fubtended by 

 an arc equal to SM : but, becaufc the arc AB is 

 60°, and the arc AG is 50° 5i'.o924, the arc' 

 BG will be 9° 8'.9076 ; the difference there- 

 fore between SM and the arc BG is o'.ooi6o2, 

 very nearly one tenth of a fecond, and is 

 more than thirty four times greater than the 

 former difference, 



Because i\.S is equal to the fum of BC, 

 CS, and PS equal to the difference ofBC, 

 CS ; it is evident, that, if, from the log. 

 tang, of half the angle ACB, the difference 

 of the logarithms of AS, SP be fubtrafted, 

 the remainder will be the log. tang, of an 

 angle, which, if added to half the angle 

 ACB, will give the angle ASB or ACD; 

 and, if fubtra(fl:ed from half the angle ACB, 

 will give the angle CBS or BCD. 



EX- 



