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LIGHT AND ELECTRICITY
Faraday had advanced as far as this in his ideas and
conjectures. He could not prove them, although he eagerly
sought for proof. He delighted in investigating the connec-
tion between light, electricity, and magnetism. The beautiful
connection which he did discover was not the one which he
sought. So he tried again and again, and his search only
ended with his life. Among the questions which he raised
there was one which continually presented itself to him-Du
electric and magnetic forces require time for their propaga-
tion? When we suddenly excite an electromagnet by a
current, is the effect perceived simultaneously at all distances?
Or does it first affect magnets close at hand, then more
distant ones, and lastly, those which are quite far away?
When we electrify and discharge a body in rapid succession,
does the force vary at all distances simultaneously? Or do
the oscillations arrive later, the further we go from the body?
In the latter case the oscillation would propagate itself as a
wave through space. Are there such waves? To these
questions Faraday could get no answer. And yet the answer
is most closely connected with his own fundamental concep-
tions. If such waves of electric force exist, travelling freely
from their origin through space, they exhibit plainly to us
the independent existence of the forces which produce them.
There can be no better way of proving that these forces do
not act across space, but are propagated from point to point,
than by actually following their progress from instant to
instant. The questions asked are not unanswerable; indeed
they can be attacked by very simple methods. If Faraday
had had the good fortune to hit upon these methods, his
views would forthwith have secured recognition. The con-
nection between light and electricity would at once have
become so clear that it could not have escaped notice even by
eyes less sharp-sighted than his own.
But a path so short and straight as this was not vouch-
safed to science. For a while experiments did not point to
any solution, nor did the current theory tend in the direction of
Faraday's conceptions. The assertion that electric forces could
exist independently of their electricities was in direct opposition
to the accepted electrical theories. Similarly the prevailing
theory of optics refused to accept the idea that waves of light