tests made, on the part of those who
were as superstitions as the people in ancient times, who urged that it
was impious to attempt to ward off Heaven's lightnings. It was argued
that the lightning was one way in which the Creator manifested His
displeasure, and exercised His power to strike the wicked.

When such writers as Pliny will gravely set forth an explanation of the
causes of lightning, as follows in the paragraph below, we can
understand why it inculcated superstitious fears in the people of
ancient times. He says:

"Most men are ignorant of that secret, which, by close observation of
the heavens, deep scholars and principal men of learning have found
out, namely, that they are the fires of the uppermost planets, which,
falling to the earth, are called lightning; but those especially which
are seated in the middle, that is about Jupiter, perhaps because
participating in the excessive cold and moisture from the upper circle
of Saturn, and the immoderate heat of Mars, that is next beneath, by
this means he discharges his superfluity, and therefore it is commonly
said, 'That Jupiter shooteth and darteth lightning.' Therefore, like as
out of a burning piece of wood a coal flieth forth with a crack, even so
from a star is spit out, as it were, and voided forth this celestial
fire, carrying with it presages of future things; so that the heavens
showeth divine operations, even in these parcels and portions which are
rejected and cast away as superfluous."

CHAPTER XVII

POWER, AND VARIOUS OTHER ELECTRICAL MANIFESTATIONS

It would be difficult to mention any direction in human activity where
electricity does not serve as an agent in some form or manner. Man has
learned that the Creator gave this great power into the hands of man to
use, and not to curse.

When the dynamo was first developed it did not appear possible that it
could generate electricity, and then use that electricity in order to
turn the dynamo in the opposite direction. It all seems so very natural
to us now, that such a thing should practically follow; but man had to
learn this.

Let us try to make the statement plain by a few simple illustrations. By
carefully going over the chapter on the making of the dynamo, it will be
evident that the basis of the generation of the current depends on the
changing of the direction of the flow of an electric current.

Look at the simple horse-shoe magnet. If two of them are gradually moved
toward