Evolution of Electricity from Magnetism
Another arrangement was then employed connecting the former experiments
on volta electric induction (6 26.) with the present. A combination of
helices like that already described (6.) was constructed upon a hollow
cylinder of pasteboard: there were eight lengths of copper wire, containing
altogether 220 feet; four of these helices were connected end to end, and
then with the galvanometer (7.); the other intervening four were also
connected end to end, and the battery of one hundred pairs discharged
through them. In this form the effect on the galvanometer was hardly
sensible (11.), though magnets could be made by the induced current (13.).
But when a soft iron cylinder seven eighths of an inch thick, and twelve
inches long, was introduced into the pasteboard tube, surrounded by the
helices, then the induced current affected the galvanometer powerfully and
with all the phenomena just described (30.). It possessed also the power of
making magnets with more energy, apparently, than when no iron cylinder was
present. Next >> |
Previous
Home
