454 



Capt. J. Hollingworfch 



on a 



the string from its lowest point, the angle which the 

 element ds makes with the vertical, and w the weight of 

 the wire per unit length. 



The normal wind-pressure is proportional to the square of 

 the normal component of wind-velocity, the tangential effect 

 will be neglected. From certain results which are not 

 available at the moment, it appears that the ratio tang, 

 force /normal force is small except when is nearly 90°, 

 and then its. chief effect will evidently be rather to increase 

 the total than to modify the shape. 



T+ctT 



Direction of 

 Kv^coste ds. motion * elocit J * 



co ds 



For equilibrium of the element ds we have by resolving; 

 along the tangent 



dT = w ds cos 6, I. 



and by resolving along the normal 



Td0=Kv 2 cos 2 Ods-w sin Ods. 

 Eliminatino- T between I. and II., 



IL 



d 



di 



(w sin 0- Kv 2 cos 2 0) + 2 cos ^ (w + Kv 2 sin 6) = 0, III. 



d0 



or writing 



To solve this : 

 Put 



w 



Ki 



ds 



= 2^COS<9 . £ 



+ sin# 



d0 2 dO ' cos 2 0- p sintf 



dd~ z " 



IV. 



dz 



+ sin 



--2-cos0 p ^ sm 

 d0~" cos 2 0-psin<9' 



dz _ cos0(p + sii\0)d0 m 

 2z " Qos*0—psin0 ; 



