Faraday as a Discoverer
Discovery of Magneto-electricity: Explanation of Argo's magnetism of rotation:
Terrestrial magneto-electric induction: The extra current.
The work thus referred to, though sufficient of itself to secure no mean scientific
reputation, forms but the vestibule of Faraday's achievements. He had been engaged
within these walls for eighteen years. During part of the time he had drunk in knowledge
from Davy, and during the remainder he continually exercised his capacity for
independent inquiry. In 1831 we have him at the climax of his intellectual strength, forty
years of age, stored with knowledge and full of original power. Through reading,
lecturing, and experimenting, he had become thoroughly familiar with electrical science:
he saw where light was needed and expansion possible. The phenomena of ordinary
electric induction belonged, as it were, to the alphabet of his knowledge: he knew that
under ordinary circumstances the presence of an electrified body was sufficient to excite,
by induction, an unelectrified body. He knew that the wire which carried an electric
current was an electrified body, and still that all attempts had failed to make it excite in
other wires a state similar to its own.
What was the reason of this failure? Faraday never could work from the experiments of
others, however clearly described. He knew well that from every experiment issues a
kind of radiation, luminous in different degrees to different minds, and he hardly trusted
himself to reason upon an experiment that he had not seen. In the autumn of 1831 he
began to repeat the experiments with electric currents, which, up to that time, had
produced no positive result. And here, for the sake of younger inquirers, if not for the
sake of us all, it is worth while to dwell for a moment on a power which Faraday
possessed in an extraordinary degree. He united vast strength with perfect flexibility. His
momentum was that of a river, which combines weight and directness with the ability to
yield to the flexures of its bed. The intentness of his vision in any direction did not
apparently diminish his power of perception in other directions; and when he attacked a
subject, expecting results he had the faculty of keeping his mind alert, so that results
different from those which he expected should not escape him through preoccupation.
He began his experiments 'on the induction of electric currents' by composing a helix of
two insulated wires which were wound side by side round the same wooden cylinder.
One of these wires he connected with a voltaic battery of ten cells, and the other with a
sensitive galvanometer. When connection with the battery was made, and while the
current flowed, no effect whatever was observed at the galvanometer. But he never
accepted an experimental result, until he had applied to it the utmost power at his
command. He raised his battery from 10 cells to 120 cells, but without avail. The current
flowed calmly through the battery wire without producing, during its flow, any sensible
result upon the galvanometer.
'During its flow,' and this was the time when an effect was expected-- but here Faraday's
power of lateral vision, separating, as it were, from the line of expectation, came into