The element Volta represented the high column made of metal circles -
copper zinc, divided by the cardboard linings moistened with a solution
of alkali or table salt.
Occurrence a column has sharply changed character of all
subsequent experiences. It has been finalised that on wires the
electric current, capable to make certain work can flow.
In 20 years after the invention Volta the Danish physicist has found
out magnetic action of an electric current on a compass arrow. This
opening often result as a typical example of casual opening. And
business was so. In 1820 Ersted showed to students experiments on an
electricity. Near to a wire on a laboratory table there was not having
any relation to experience a compass. One of students has paid
attention of the professor that when the current joins, the arrow of a
compass, shudders and turns. At deenergizing of a current it again
comes back in a starting position.