rd, striking the corner of the barn, cutting it off as
smoothly as though done with some sharp-edged tool, but it in no other
way affected the rest of the building. One would suppose that the
centrifugal force developed in this whirling motion would cause the cone
to fly apart, and why it does not no one certainly knows. But we are
obliged to accept the fact.

These cases are cited to show that motion gives rigidity to substances
that in the quiescent state are mobile or easily moved, like the straw
or the air. If we should assume that there are infinitesimal vortices or
whirling rings in the ether, of such rapidity as to give it different
degrees of rigidity, we can get a glimmering idea of how an atom of
matter may be formed from ether.

Referring to the rigidity which motion gives to ordinary matter, it is
well known that when two vessels at sea collide the one having the
higher speed is not so liable to injury as the one with the lower. The
reader will perhaps remember a circumstance said to have occurred a few
years ago on the Lake Shore Railroad, between Buffalo and Cleveland. The
limited express was going west, and while rounding a curve the engineer
suddenly came in sight of a wrecked freight train, a part of which was
lying on the track where the express train had to pass. The engineer saw
that he was too near the wreck to stop his train and that the only way
to save his own train and the lives of his passengers would be to cut
through the wreck. He pulled out the throttle and put on a full head of
steam, and when the train struck the wreck it was going at such a high
rate of speed that it cut through without seriously damaging the train
and without harm to the passengers.

There are other heroes beside those who lead armies in battle.

CHAPTER VIII.

CLOUD-FORMATION--EVAPORATION.

Water exists in different forms without, however, undergoing any
chemical change. It is when condensed into the fluid state that we call
it "water," and then it is heavier than the atmospheric air and
therefore seeks the low places upon the earth's surface, the lowest of
which is the bed of the ocean. Wherever there is water or moisture on
the face of the globe there is a process going on at the surface called
evaporation. This process is much more rapid under the action of heat
than when it is colder. In other words, as the heat increases
evaporation increases within certain limits and bears some sort of a
ratio to it