216 Mr Oreenhill, On the Rotation of a [March 20, 



(2) in region II. b 2 > a 2 > c 2 , and we must put 



a 2 + X=(6 2 -c 2 )-^-, 



& 2 + \=(& 2 -c 3 )— ^ , 



y sm 2 | 



t + X-p-J)™**., 



' smf 



tf=^9> p = cos-0, 



and 



1 COS (i 



A 2 (/>' J A 2 (/> 



and then the values of -4, B, G in region II. will be the values of 

 B, A, G respectively in region I. 



(3) in region III. b 2 > c 2 > a 2 , and we must put 



a * + X=(i*- a *)^, 



sin y 



fc 2 + \ = (& 2 _ « 2 ) 



sin^y ' 



and 



sin y 



c 2 A2JL a 2 



£2=A0, 72= COS" 0, 



1 A 2 <f> 



or « = — ¥T , y- 7,\ 



COS * cos 2 </> 



and then the values of A, B, G in region III. will be the values of 

 C, A, B respectively in region I. 



A B G 



The following tables give the values of -; — - , -: — and - — , 



4nrp <±7rp -iurp 



for values of 6 and </> proceeding by increments of ^tt, or, ex- 

 pressed in degrees, for 0°, 15°, 30°, 45°, 60°, 75°, 90°; the vertical 

 columns for constant values of 9, and the horizontal lines for con- 

 stant values of (p. 



