PHYSICAL anv LITERARY. 143 
degrees and minutes inan angle fubtended 
by an arc equal to SM: But, becaufe the 
arc AB is 60°, and thearc AG is 50° 
§1'.0924, the arc BG will be 9°8'.9076 ; 
the difference therefore between SM and 
the arc BG is 0’.001 602, very nearly one 
tenth of a fecond, and is more than thirty- 
four times greater than the former dif- 
ference. 
! 
‘ 
4 
Because AS is equal to the fum of BC, 
CS, and PS equal to the difference of BC, 
CS; it is evident, that if, from the log. © 
tang. of half the angle ACB, the difference 
of the logarithms of AS, SP be fubtracted, 
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@ted from: half the angle 
ACB, will give the angle CBS or BCD;> 
4 ' d 
EX AMY P LBA 
In the orbit of Mars, the mean diftance 
is to the excentricity as 152369 to T4100. 
Suppofing the mean anomaly to be’ 19, it 
is required to find the anomaly of the ex- 
centric, : 
The 
