The 20 years following the announcement of the voltaic-pile invention
were years of intense experimental activity with this device. Many new
chemical elements were discovered, beginnings were made on the
electrochemical series of the elements, the electric arc and
incandescent platinum wires suggested the possibilities of electric
lighting, and various electrochemical observations gave promise of other
practical applications such as metal-refining, electroplating, and
quantity production of certain gases. Investigators were keenly aware
that all of the available means for measuring and comparing the
_electrical_ aspects of their experiments (however vaguely these
"electrical aspects" may have been conceived), were slow, awkward,
imprecise, and unreliable.
The atmosphere was such that prominent scientists everywhere were ready
to pounce immediately on any reported discovery of a new electrical
"effect," to explore its potentialities for instrumental purposes. Into
this receptive environment came H. C. Oersted's announcement of the
magnetic effects of a voltaic circuit, on July 21, 1820.[9]
[Illustration: Figure 2.--"GALVANOMETER" WAS THE NAME given by Bischof
to this goldleaf electrostatic instrument in 1802, 18 years before
Ampère coupled the word with the use of Oersted's electromagnetic
experiment as an indicating device.]