44 



EXPERIMENTS IN AERODYNAMICS. 



Table XI.— August 24, 1889. 

 Barometer, 734.3 mm. ; mean temperature, 25°.0 C. ; wind, light. 



The actual velocities obtaining in the individual observations varied some- 

 what ; for the lowest velocity ranging between 5 and 8 ; for the second velocity 

 ranging between 12.5 and 13.o, and for the highest velocity rjinging in gen- 

 eral between 22.5 and 24.0, except for the planes 6 inches apart, for which the 

 A^elocities were about 19 meters per second. The numerical results for the 

 lowest and the highest speed will be found plotted in Figs. 6 and 7, respectively. 

 In these diagrams the abscissre are angles of inclination of the planes to the 

 horizon, and the ordinates are times of falling. For the highest velocity, the 

 times of falling of the single pair of planes and of the double pair, both, 4 inches 

 and 6 inches apart, are alike, while for the planes 2 inches apart, the time of falling 

 is shorter. For the lowest velocity, viz., 6.5 meters per second, the planes 4 inches 

 apart as well as those 2 inches apart fall a little faster than the single plane, 

 and are therefore not quite so well sustained by the air. 



This result confirms the statement above made, that for double sets of j)lanes, 

 one above the other, the maximum supporting eifect relatively to the single 



