ON THE MOTION OF PROJECTILES. 
239 
mentally verified, by dropping shot down a mine in Germany, when it 
was found that they always fell a little to the east, though of course the 
amount of the deflection could not be accurately observed. 
If a stone is projected vertically upwards the equations are 
(£>H z . / gt\ 
sin 4 > cos $ l w_ 4 ) 
y=-ozt 2 ‘ cos 4> (w - 
( qt\ co 2 t 3 „ , 
z — t\w 1 —— w COS 2 (j) 
(16), 
from which it appears that the deflection is initially to the west and 
north. But if the stone continues to fall freely, after a time 2 
(approximately) it returns to the level of the point of projection, after 
w . w 
time 3 - it passes to the east of it, and after a time 4 - to the south of 
9 . 9 
it (in north latitudes, or vice versa). 
