‘ 
MURPHY: POWER OF A TWELVE FOOT ‘‘POWER’’ WINDMILL. 1195 
PRESSURE ON AN INCLINED PLATE. 
Newton’s formula for fluid pressure on a plate inclined at an 
angle 8 with the direction of motion of the fluid is 
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2o 
5 
Measurements of this pressure on inclined plates show that this 
formula has not the correct form: Prof. 5S. P. Langley’s exper- 
ments show that wind pressure on an inclined surface is normal to 
the surface, varies with the shape of surface and the direction of 
the longest edge, whether at right angles to direction of wind or 
parallel to it, and that the pressure is much larger than that given 
by Newton’s formla. Fig. 2 shows curves given the relation be- 
B 
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