114 EXPERIMENTS ON THE FROUDE. 
APPENDIX C. 
A METHOD oF ALLOWING FOR WIND RESISTANCE. 
By H. A. EVERETT, MEMBER. 
Let Rw = Wind resistance. 
Vw = Speed of wind past the ship. 
aes V'w0= Speed of wind. 
Speed of ship. 
Resistance of ship. 
aN 
tl 
Fic. 32. 
When the ship is going against the wind; 
Ve=V+V'w 
and when going with the wind, 
Vo=V—V'e. 
Froude gives for wind resistance, 
IGS IAL 
where K is a constant and 4 is the area of the transverse contour above 
the L. W. L. 
Rw % Vo 
From the experimental curves we get R, and R, at any desired 
speed of the ship V. 
Then— 
R against — R+ Ru and (1) 
R with — R—-Ro (2) 
R against — R+KA ( V+ V'w)? (3) 
Rema | = KR A (VeVi) (4) 
R against _ R with — KA {( V+ V'u)? + ( v= V'w)"} ; 
TRS patie ales , ’ 
= (VV e+ (V— Ve)? 
lt i i a 
