a Problem in physical Astronomy . 563 
First, for the value of A, 
Numbers. Logarithms. Numbers. 
Here a = 1*5236,71 "1* 0*1828,913 
and 6 = 1*4451,60 J Ar. c 1*8400,841 
d « b = 0*0785,11 
3-8949.305 
a + b =5 2.9688,31 
0-4725.855 
£t b 
<l + b —* cc 
2*4223,450 
2 
«c 
1*8786,850 
- 75-62841 =~ 
0 1 S/3 1 o — e 
fee 
"3-4380.4 
0*00274 —fee 
cc . 
g 
2*244 
Sum of these two logs. 
5*682 - 
t 0*00005 ^ ge* 
The sum of these four terms is 
75’82435 
Having now found the value of the four terms — 4- e 4 - fee 
C C * \ J 
4rgc\ we must next find the value of the three logarithmic 
terms a -f ^ ct.ee + 'uc\ which may quickly be done as 
follows : 
Half the logarithm of cc is 1*211 1,725= the sine of 9 0 21' 
32"*28; and half this angle is 4 0 40' 46 // *i4, the logarithmic co- 
tangent of which is 1*0869,576; and this common logarithm 
* I was favoured with these numbers by Dr. Maskhlyne. 
