THE PLANE-DROPPER. 



41 



Exp< riments to determine the time of falling of two s '■ of planes, one above the other (second i 



Table IX.— August 22, 1889. 



F. W. Very, Conducting experiments. 



Barometer, 731.8 mm. ; mean temperature, 23°.9 C. ; wind, light. 



Result: It is certain that any angle greater than + 1° (with planes 6 indies apart) would 

 produce soaring, and as the error of verticality in this day's observations probably does not 

 exceed 1° during motion, we may take about 2° as the soaring angle for the speeds used. 



