200 KANSAS UNIVERSITY QUARTERLY. 
0.001600xX. 515 i 
Galan) 9°91. 481 a lay (R7O-evt26)c" 
| Wg OE) i | 
559 
.0000787c3 (25) | 
¢ being in feet per second. 
Equation (25) is a cubical parabola and is the curve AN shown 
Gaye male ge) one | 
TOTAL POWER OF WIND. 
The total energy of the wind which strikes the fans of this mill 
is kinetic energy, KE--{Mc*, M being the mass of air striking the | 
fans per second and c the wind velocity in feet per second. 
M-==volume multiplied by heaviness and divided by acceleration of : 
gravity, and volume—area A multiplied by c, hence we have 
Siea nt yvAc3 
Ko! (260) 
| Dividing (26) by 550 to reduce to horse power we have : 
Ac® 
CE ki (27) | 
28550 
Substituting for y, A and g their values for the atmospheric condi- | 
| tions we have CHP ysniQooT s0c" (28) { 
q Equation (28) is a cubical parabola. It differs from (25) only in 
the value of the coefficient, which is about twice trat of (25). This | 
| equation is represented by the curve AB, afeaay 
i It appears then from (25) and (28) that this mill when loaded i 
BT with a uniformly increasing useful load is using at all wind veloci- 
i ties ‘about half the energy of the air which strikes its fans. From | 
" | . . + { 
| (25) and (2) it appears that the total power that this mill takes f 
| from the wind varies as the cube of the wind velocity, but that the | 
i, . . 6 F . 
i useful power yielded varies only as the square of the velocity. \ 
\ 
| 
