MR. R. V. SOUTHWELL ON THE GENERAL THEORY OP ELASTIC STABILITY. 215 



and 



^-gf3 = 0, . . (69) 



and these equations involve the fifteen coefficients 



o !> in i ?i> M"-MO 



From equations (57-59) we may obtain nine other relations between these 

 coefficients, as follows : 



m- 



+ -Z-)+T<r 



1 m 



-8 A 



-4 A 



A-B 



i-2 4 



a- 



(72) 



