Many writers have expressed surprise that with all the use made of
voltaic cells after 1800, including the enormous cells that produced
the electric arc and vaporized wires, no one for 20 years happened to
see a deflection of any of the inevitable nearby compass needles, which
were a basic component of the scientific apparatus kept by any
experimenter at this time. Yet so it happened. The surprise is still
greater when one realizes that many of the contemporary natural
philosophers were firmly persuaded, even in the absence of positive
evidence, that there _must_ be a connection between electricity and
magnetism. Oersted himself held this latter opinion, and had been
seeking electromagnetic relationships more or less deliberately for
several years before he made his decisive observations.
His familiarity with the subject was such that he fully appreciated the
immense importance of his discovery. This accounts for his employing a
rather uncommon method of publication. Instead of submitting a letter to
a scientific society or a report to the editor of a journal, he had
privately printed a four-page pamphlet describing his results. This, he
forwarded simultaneously to the learned societies and outstanding
scientists all over Europe. Written in Latin, the paper was published in
various journals in English, French, German, Italian and Danish during
the next few weeks.[10]
In summary, he reported that a compass needle experienced deviations
when placed near a wire connecting the terminals of a voltaic battery.
He described fully how the direction and magnitude of the needle
deflections varied with the relative position of the wire, and the
polarity of the battery, and stated "From the preceding facts, we may
likewise collect that this conflict performs circles...." Oersted's
comment that the voltaic apparatus used should "be strong enough to heat
a metallic wire red hot" does not excuse the 20-year delay of the
discovery.