580 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



TABLE II. 

 August 28. Light Pressure. Ballistic Measurements. Air. 



suring the distance between the centres of the images when on the east 

 and west vanes (by the dividing engine T. 2 , Fig. 3) and dividing by two. 



The columns headed 



C. + A 



Rand 



c B + n e 



Pg are the average 



