380 APPENDIX CALCULATION OF THE 



A 4 rr 45 23' 26", which may be thus found. 



cos A = R ' cos ' 7> R ' cos> 5r 32/ 

 4 ~ 



sin. 60 sin. 60 



log. R . . . . = 10- 



log. cos. 5V 32' 30" = 9-7840353 



19-7840353 

 log. sin. 60" . . = 9-9375306 



s . cos.^ 4 . . = 9-8465047 



Therefore angle A 4 = 45 23' 26". 

 A 5 109 8' 11". 

 A 6 =i 70 51' 49". 



The following ratios may be known from the tables 

 of natural sines, &c. when we require the nearest 

 whole numbers by which they may be represented; 

 or their logarithms may be taken from the tables, 

 when we use logarithms only in our calculations. 



Perpendicular on axis drawn from lateral solid 

 angle : axis :: tan.^ 3 : R :: i tang. 63 44' 45" : R 

 :: i 2*0274279 : 1 :: -6758093 : 1. 



This may be reduced with sufficient accuracy to 

 its lowest equivalent terms in whole numbers, by 

 means of a common sliding rule, and will be found 

 as 23 : 34 very nearly. 



Or if the logarithms be required, we have 

 log. tang. 63 44 ; 45" = 10-3069454 

 log. 3 ...-. 0-4771213 



9-2298241 



log. R =10 



0-0701759 



