y, and Philosophy tells us to base our theories and
hypotheses on experience and experiment. Now what does experiment and
experience teach us as to the effect of a body revolving in any medium
upon that medium? If experience teaches us anything at all, it teaches
us that the further away any medium is from the revolving body, the less
is the angular velocity of that medium at that distance, while the
nearer the medium is to the revolving body, the greater is the angular
velocity.

This applies in each and every case, whether the medium is either fluid
or gaseous, and I will challenge the reader to perform any experiment on
any solid body rotating in a fluid or gaseous medium, and prove by that
experiment that the angular velocity of the outermost part of the fluid
or gaseous medium is equal to the angular velocity of the medium
directly associated with the body, or even at a short distance from it.

But we have most conclusive evidence of the fact that a solid body does
not communicate all its rotational surface motion to the medium directly
in contact with that body in the case of the earth revolving on its
axis, surrounded by an atmosphere. If the principle held good anywhere
in relation to a revolving body, viz. that the whole of the rotational
velocity is communicated to the medium surrounding the body, it should
certainly hold good at the surface of the body where the two media, the
solid and gaseous media, meet.

If a solid body fails to impart all its rotational velocity to the
medium there, then it will certainly fail to impart its full rotational
velocity to the enveloping medium 100 miles away, and fail still more at
a distance of 1000, and still more at a distance of 100,000,000, and so
on proportionate to the distance.

What, then, is the effect of the rotational velocity of the surface of
the earth on the atmosphere near to it? We know that the velocity of the
surface of the earth is greatest at the equator, as at that place the
circumference of the earth is about 25,000 miles, but the further we get
away from the equator, and the nearer we get to the North and South
poles, the velocity of the surface decreases, simply because the
circumference of the earth decreases.

Or, to reverse the statement, the velocity of the surface of the earth
is least at the poles, but increases the nearer we get to the equator.
It is also familiar knowledge that there are currents of cold air ever
moving from the North an