PHYSICAL PROPERTIES. 
17 
from the hand of the Divine Architect. A few prac- 
tical examples will show the importance of a knowl- 
edge of this principle, which, though taught by ob- 
servation and even by instinct, is, nevertheless, 
often lost sight of in the daily walks of life. 
If a carriage, horse, or boat moving with speed 
be suddenly stopped, the passengers, riders, or any 
loose bodies which are carried will be precipitated 
in the direction of the motion ; because, by their in- 
ertia, they are disposed to persevere in the motion 
which they shared in common with that which 
transported them. So, also, if a passenger leap 
from a carriage in rapid motion, he will fall in the 
direction in which the carriage is moving at the mo- 
ment his feet touched the ground, because his body, 
on quiting the vehicle, retains, by its inertia, the 
motion which it had in common with it. In such a 
case, it would be far safer to leap as far as possible 
into the air, so that, by the time he strikes the earth, 
the momentum of the body may have been lost ; for 
the reason a person falls under such circumstances 
is, that while motion is destroyed by the resistance 
of the ground to the feet, it is retained in the upper 
part of the body, so that the same effect is produ- 
ced as if the feet had been tripped. In starting a 
train of loaded cars upon a railroad, we see that a 
considerable amount of power is neccesary to com- 
municate motion; but afterward, very little force 
comparatively is required, only sufficient to over- 
come the friction of the rails, which is shght. The 
same holds true of loaded vehicles drawn by oxen 
or horses. 
There can be no doubt that this property is in- 
stinctively taught to the brute creation. For ex- 
ample, in coursing, when the hare is closely pursued 
by the greyhound, she suddenly doubles, that is, 
turns back upon her course, at an oblique angle 
with the direction in which she had been running, 
while the hound, being much heavier, is unable to 
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