14 Ravleigii, The MccJiaiiical Principles of Flight. 



reaches a maximum in the nci<;hbourhood of 27°. The 

 results are shown in A {Fig. /), or in the second column 

 of the accompanying table. The scale of the ordinates is, 

 of course, arbitrary. The efficiency for 5" is assumed 

 to be 10. 



In order to deduce the normal pressure, the results for 

 the rotatory efificiency must be divided by cos a, and 

 accuracy is necessarily lost in the case of the larger angles. 

 Tlie numbers thus arrived at are plotted in curve B, and 

 arc given in the third column of the table, reduced so as 

 to make the maximum (at 90''') equal to 100. As regards 



