ago foresaw them, and that Michael
Faraday discovered them? It would be a delicate, and also a rather
puerile task, to class men of genius in order of merit. The merit of
an inventor like Edison and that of a theorist like Clerk Maxwell have
no common measure, and mankind is indebted for its great progress to
the one as much as to the other.

Before relating how success attended the efforts to utilise electric
waves for the transmission of signals, we cannot without ingratitude
pass over in silence the theoretical speculations and the work of pure
science which led to the knowledge of these waves. It would therefore
be just, without going further back than Faraday, to say how that
illustrious physicist drew attention to the part taken by insulating
media in electrical phenomena, and to insist also on the admirable
memoirs in which for the first time Clerk Maxwell made a solid bridge
between those two great chapters of Physics, optics and electricity,
which till then had been independent of each other. And no doubt it
would be impossible not to evoke the memory of those who, by
establishing, on the other hand, the solid and magnificent structure
of physical optics, and proving by their immortal works the undulatory
nature of light, prepared from the opposite direction the future
unity. In the history of the applications of electrical undulations,
the names of Young, Fresnel, Fizeau, and Foucault must be inscribed;
without these scholars, the assimilation between electrical and
luminous phenomena which they discovered and studied would evidently
have been impossible.

Since there is an absolute identity of nature between the electric and
the luminous waves, we should, in all justice, also consider as
precursors those who devised the first luminous telegraphs. Claude
Chappe incontestably effected wireless telegraphy, thanks to the
luminous ether, and the learned men, such as Colonel Mangin, who
perfected optical telegraphy, indirectly suggested certain
improvements lately introduced into the present method.

But the physicist whose work should most of all be put in evidence is,
without fear of contradiction, Heinrich Hertz. It was he who
demonstrated irrefutably, by experiments now classic, that an electric
discharge produces an undulatory disturbance in the ether contained in
the insulating media in its neighbourhood; it was he who, as a
profound theorist, a clever mathematician, and an experimenter of
prodigious dext