18 THEORY OF SHIP WAVES AND WAVE RESISTANCE. 
7. The general expression (10) now gives, with p=2gl/c2, a=gd/c*, 
B=d/2l. a 
2 TP 2 
R= en it (1—e-asec?o | cos*d + <008" 
0 
+ (cos? o- z cos* 2) cos (p sec $) - 4 cost¢ sin (psec $) }ag, . (15) 
After certain transformations, this expression was evaluated by 
approximate methods to give the curves of Fig. 8 for the cases B=~, 0-1 and 0-05. 
(Proc. Roy. Soc. A., 108, p. 582. 1925.) 
264 
