e this could have been very
dangerous, but he had foreseen it and had supported the string through
an insulator. He observed that this electricity had the same
properties as the static electricity produced by friction.

But long before Franklin many other scientists had carried out
research into the nature of electricity.

In England William Gilbert (1544-1603) had noticed that the powers
of attraction and repulsion of two non-metallic rods which
he had rubbed briskly were similar to those of lodestone and amber--they
had acquired the curious quality we call magnetism. Remembering
Thales of old he coined the word 'electricity'.

Otto von Guericke (1602-1686) a Mayor of Magdeburg in Germany, was
an amateur scientist who had constructed all manner of gadgets. One
of them was a machine consisting of two glass discs revolving in
opposite directions which produced high voltage charges through
friction. Ramsden and Wimshurst built improved versions of the
machine.

A significant breakthrough occurred when Alessandro Volta
(1745-1827) in Italy constructed a simple electric cell (in 1799)
which produced a flow of electrons by chemical means. Two plates, one
of copper and the other of zinc, were placed in an acid solution and a
current flowed through an external wire connecting the two plates.
Later he connected cells in series (voltaic pile) which consisted of
alternate layers of zinc and copper discs separated by flannel discs
soaked in brine or acid which produced a higher electric pressure
(voltage). But Volta never found the right explanation of why his cell
was working. He thought the flow of electric current was due to the
contact between the two metals, whereas in fact it results from the
chemical action of the electrolyte on the zinc plate. However, his
discovery proved to be of incalculable value in research, as it
enabled scientists to carry out experiments which led to the
discoveries of the heating, lighting, chemical and magnetic effects of
electricity.

One of the many scientists and physicists who took advantage of
the 'current electricity' made possible by Volta's cells was Hans
Christian Oersted (1777-1851) of Denmark. Like many others he was
looking for a connection between the age-old study of magnetism and
electricity, but now he was able to pass electric currents through
wires and place magnets in various positions near the wires. His
epoch-making discovery which established for t