MACHINE PERFORMANCE CURVE 113 



by the method of Chapter X., page 98 : this value is to be used 

 for the present calculation. 



h^ is the height in feet of the centre line of the propeller shaft 

 above the line of action of the body resistance. This line of 

 action has already been found by the method of Chapter VIII., 

 page 77. 



^ 2 is the height in feet of the centre line of the propeller 

 shaft above a point halfway between the top and bottom leading 

 edges. 



R! and R 2 are the body resistances in pounds at 100 miles 

 per hour, already found by the method of Chapter VIII., page 

 77, R x corresponding to parts in the slip stream, and R 2 cor- 

 responding to the rest of the machine. 



k^ max and L/D are corrected values for values of X from 

 I to i-o, and have already been found by the method of 

 Chapter IX., page 85, where they will be found in the last 

 column of the first table. 



k c is the centre of pressure coefficient, to which no corrections 

 need be applied. 



V is the speed of the machine in miles per hour in standard 

 density air. 



P is the effective horse-power required to maintain horizontal 

 flight at V miles per hour in standard density air. 



Now write down the numerical values of W, S, S', / LWflAr , 

 R.J, R 2 , c, /, /', d, h ly and h z . 



Then work out and write down the numerical values of 



367/WS' 



10* 



d = -0051^^5 



a = W/ j3 = ad' + b'c 



A' = &' B' = PC 



C = hjj D' = h^C - (hi - 



Then construct a table in the following form : 



