Murthy 



where 



* = <* p " *„> * + ( ^p - *o > * + <*p - Z c) ft 



x ' = x_, - z' = x + h sin 6 



o G G <j 



z ' = z„. - z 



,, cos d - z - h (1 - cose) 



o ~G' " G' " " G 



and if (x, y, T) are the co-ordinates of P 



r' = (x - x - h sine) i + y j + 



r - z + 



h Q (1 - cose) 



£ 



and therefore 



M, 



■/A [ 



x A A 



(x - x - h sine) l + y j 



|r- z + h G (1 - cose) 



A v A A] 

 f i + S i - k dxdy 

 x y J 



where the cross denotes the vector product 

 i. e. M^ 



" f{ Ps [~{ Y + [ f - i + h c (1 - cosS) ] 



Jx - x - h sinO+ f - z + h (1 - cose) ^ 

 |(x - x - h G sine) r -Y f x > M dxdy 



', s 



180 



