of Projectiles thrown from Cannon. 223 



24-7 grammes, and each of them was projected with half 

 its weight of powder. 



The following is the formula employed to calculate the 

 velocity of the balls. 



The semi-circumference, which has unity 

 for radius r - " " 



The ratio between the respective numbers 

 of the turns made at the same time by the 

 wheel of the axle and the pulley of the axis 

 of the disks - - - 



The time employed by the wheel of the 

 axle to make ?i number of turns 



The distance of the hole made by the ball 

 in the second disk from the axis of the disks 



The arc passed over by that hole, while the 

 disk goes from the one to the other 



The distance between the two disks 



Velocity of the ball between the disks 



We have then the following equation : 



V = il^ . -^^. 

 kt a 



As it may be of some use to add to this formula a table 

 of some experiments, we shall give the six following, made 

 with the musketoon. 



= *= 3-141 



= t 



= a 

 = b 

 = V 



Mean velocity = 390-43. 

 Constant value of k =■ ^-^^-^ . 

 All the values of a are referred tp that of r = 1 metre. 



3 The 



