210 THE ESSEX NATURALIST.
He had at last succeeded in inducing a current to flow in an ad-
jacent but separate circuit. This observation literally linked
electricity and magnetism. He had, in his own words, "evolved
electricity from magnetism."
Men who have developed the application of Electro-Magnetic
Induction.
Faraday's inspiration to seek scientific truth was doubtless
an outcome of the spirit of his age. His discoveries stand out
against the background of the work of his contemporaries.
Without this stimulus his genius may not have blossomed so fully.
The development of applications of his discoveries involved
a succession of outstanding men. But for the fortuitous accident
of their birth material progress in our industrial world would
certainly have taken place, but far more slowly. We might have
been living twenty years before our present time in this respect!
Faraday gained knowledge from experiment. He had the
unique type of mind and imagination required to originate clear
mental pictures of the physical processes involved. On these
substantial foundations Clerk Maxwell, some time of King's
College, London (born 13th June, 1831) turned Faraday's physical
conceptions into formula. His mathematical calculations led
to the then speculative Electro-Magnetic theory of light. Maxwell
never succeeded in producing electro-magnetic waves, but his
theory was explored by ingenious experimenters who have
evolved the broadcasting of to-day.
Systematic measurement, in units rational rather than
arbitrary, is consequent on calculation. In Faraday's time
pressures were stated in terms of the type and number of batteries
used—not in volts. The work of John W. Strutt, 3rd Baron
Rayleigh, has enabled electrical engineering to lend itself to
more precise measurement than is possible in other branches of
engineering.
The widespread utilisation of electricity ensued only when
consuming devices—meeting definite human needs—were
developed. The powerful, unsteady, light of the electric arc
—known over 100 years ago—was unsuitable for the ordinary
home. Sir Joseph Wilson Swan gave us a lamp suitable for the
plain man and his wife. It supplied an ancient human need in
more convenient and cleanly form. From mansion to cottage