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The first man to research the properties of the lodestone
(magnetic iron ore), William Gilbert famously published his
findings in De Magnete ('The Magnet') - findings that greatly
impressed astronomers such as Johannes Kepler and Galileo.
The magnet - as part of a compass - was to prove invaluable
to sailors on treacherous journeys across the world's oceans;
ships' navigators could now chart their course with much
greater accuracy. Galileo expressed an interest in Gilbert's
work in letters to his fellow scientists Fra' Paolo Sarpi and
GF Sagredo, and it has been argued that Galileo's attempt at
creating a magnetic lodestone for his patrons was inspired by
his reading of De Magnete.
William Gilbert was born into a fairly wealthy family in
Colchester, Essex. He was educated at Cambridge University,
where he received a BA, MA and MD, after which he became a
senior fellow. His scientific status was further recognised
when he became President of the Royal College of Physicians in
1600, having practised as a doctor in London and its environs
for some years. He was also appointed physician to Queen
Elizabeth I.
That same year, 1600, De Magnete was published, and was
quickly accepted as the standard work on magnetism and
electrical phenomena throughout Europe. In it, Gilbert
distinguished between magnetism and static (known as the amber
effect). He also compared the magnet's polarity to the
polarity of the Earth, and developed an entire magnetic
philosophy on this analogy.
Gilbert's findings suggested that magnetism was the soul of
the Earth, and that a perfectly spherical lodestone, when
aligned with the Earth's poles, would spin on its axis, just
as the Earth spins on its axis over a period of 24 hours.
Gilbert was in fact debunking the traditional cosmologists'
belief that the Earth was fixed at the centre of the universe,
and he provided food for thought for Galileo, who eventually
came up with the proposition that the Earth revolves around
the Sun.
This comprehensive review of magnetism was the first of its
kind, and after Gilbert's death, a collection of his
unfinished and previously unpublished work was assembled by
his half-brother, with the title De Mundo Nostro Sublunari
Philosophia Nova ('New Philosophy about our Sublunary World').
This second publication proved much less successful than the
first, which remained seminal in the development of scientific
thought. | 