1910] 



on the Dynamics of a Golf Ball. 



807 



awaj to the right, behaving like a sliced ball. I reverse the direction 

 of the force and make it act upwards, and the pa,rticles curve away to 

 the left, just like a pulled ball. 



By increasing the magnetic force we can get slices and pulls much 

 more exuberant than even the woi'st we perpetrate on the links. 



Though the kinks shown in Fig. 20 have never, as far as I am 

 aware, been observed on a golf-links, it is quite easy to produce them 



Fig 



if we use very light balls. I have here a ball A made of very thin 

 india-rubber of the kind used for toy balloons, filled with air, and 

 weighing very little more than the air it displaces ; on striking this 

 with the hand, so as to put underspin upon it, you see that it describes 

 a loop, as in Fig. 24. 



Striking the ball so as to make it spin about a vertical axis, you 



€ 



see that it moves off with a most exaggerated slice w^hen its nose is 

 moving to the right looking at it from the tee, and with an equally 

 pronounced pull when its nose is moving to the left. 



One very familiar property of slicing and pulling is that the 

 curvature due to them becomes much more pronounced when the 

 velocity of the ball has been reduced, than it was at the beginning 

 when the velocity was greatest. We can easily understand why this 



