e is no movement of electrons without this attendant field of
energy, and their motion is not stopped until that field of energy
disappears from the ether. The modern theory of magnetism supposes that
all magnetism is produced in this way. All magnetism is supposed to
arise from the small whirling motions of the electrons contained in the
ultimate atoms of matter. We cannot here go into the details of the
theory nor explain why, for instance, iron behaves so differently from
other substances, but it is sufficient to say that here, also, the
electron theory provides the key. This theory is not yet definitely
_proved_, but it furnishes a sufficient theoretical basis for future
research. The earth itself is a gigantic magnet, a fact which makes the
compass possible, and it is well known that the earth's magnetism is
affected by those great outbreaks on the sun called sun-spots. Now it
has been recently shown that a sun-spot is a vast whirlpool of electrons
and that it exerts a strong magnetic action. There is doubtless a
connection between these outbreaks of electronic activity and the
consequent changes in the earth's magnetism. The precise mechanism of
the connection, however, is still a matter that is being investigated.

ETHER AND WAVES

Ether and Waves

The whole material universe is supposed to be embedded in a vast medium
called the ether. It is true that the notion of the ether has been
abandoned by some modern physicists, but, whether or not it is
ultimately dispensed with, the conception of the ether has entered so
deeply into the scientific mind that the science of physics cannot be
understood unless we know something about the properties attributed to
the ether. The ether was invented to explain the phenomena of light, and
to account for the flow of energy across empty space. Light takes time
to travel. We see the sun at any moment by the light that left it 8
minutes before. It has taken that 8 minutes for the light from the
sun to travel that 93,000,000 miles odd which separates it from our
earth. Besides the fact that light takes time to travel, it can be shown
that light travels in the form of waves. We know that sound travels in
waves; sound consists of waves in the air, or water or wood or whatever
medium we hear it through. If an electric bell be put in a glass jar and
the air be pumped out of the jar, the sound of the bell becomes feebler
and feebler until, when enough air has been taken out, we do n