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 play--he noticed that a