Prooft of OutFenis upon the Earth's siurfacé. 101 
ways been considered a subject of deep interest, and have 
given rise to different theories, none of which are satisfactory, 
and however we may be inclined at times, in despair, to aban- 
don as hopeless, the inquiry in what manner they have been 
brought about, it will occasionally force itself upon us. 
When we meet an immense mass of rounded pebbles, at a 
great distance from the bed of any river, nay almost on the 
tops of mountains, we cannot but speculate on the question 
how they came there. 
It has appeared to me that the most simple mode of account- 
ing for some, if not all of these appearances, is the supposi- 
tion that a change has at some period taken place in the ve- 
locity of the earth’s motion on her axis. 
he surface of the earth on the equator revolves at the rate 
of. more than 1000 miles per hour, or nearly 1500 feet per 
second, a rapidity of motion, of which it is not easy to form a 
very precise idea, without comparing it with other velocities, 
which are familiar tous. Thusit is greater than that of 
sound, which is estimated at 1100 feet per second, and the 
greatest speed of a ball, impelled by gunpowder, being about 
1700 feet per second, we may safely assume the velocity of 
the rotary motion of the earth at the equator, as equal to to the 
<j 
We have no idea of circular motion bearing any propor 
tion to it. The surface of a spindle of three inches diameter, 
revolving 4000 times a eed passes through only 50 feet of 
ce per second—and a wheel of wrought iron, of three feet 
diameter, will, it is said, “fly 3 in pieces before it reaches a velo 
city of 400 feet per er second. 
It is true this effect would be produced on the whidel by the 
centrifugal force, which acts with small comparative power 
mesg earth, on account of its vastly greater diameter. 
h respect to the water, floating on the earth’s surftice/*and 
held so nicely balanced by the power of gravitation, it evi- 
~— rust possess this same impetuous motion with the sol- 
id parts of the globe, and should the rotary motion of the 
earth suddenly cease, from any cause not acting equally shoe 
