MAGNETISM DURING THE SEVENTEENTH CENTURY HH Ricker III

together in history. The list of first-rate minds includes the names Kepler, Galileo, Descartes,
Pascal, Newton, Leibnitz, Fermat, and Huygens. Significantly, the list excludes William Gilbert.
None of these great minds made significant contributions to the sciences of electricity or
magnetism. We know that Kepler, Galileo, Descartes, Newton and Huygens studied magnetism
but did not make great discoveries or contributions. Only Descartes developed a magnetic
theory; unfortunately a flawed one that was influential for a hundred years. The hidden secrets of
electricity and magnetism remained securely locked away after the intellectual assaults of these
brilliant minds. The wave of progress which occurred during the scientific revolution of the
seventeenth century washed over magnetic science and left it behind, almost the same as it was
at the beginning the century.
One measure of scientific progress is the discoveries or new facts that have been added to
science. Based upon this criteria, progress in magnetic science was not significant. The
mechanical demonstrations developed by Henry Power and Robert Hooke showed that
magnetism could be induced mechanically. But, these new facts are not deemed important today.
The missed opportunities are more significant.
Galileo missed the opportunity to make the important discovery that a magnet can both attract
and repel iron or steel. This is an important magnetic effect. Gilbert failed to detect it as well. He
insisted that Albertus Magnus was wrong in his discovery that a magnet could both attract and
repel iron. The effect results from the fact that a strong magnetic field is needed to reverse an
induced magnetic field. Galileo shows how the result can be used in an entertaining why. But he
failed to publish his results.
The discovery of compass reversal by lightning should have been followed up with the discovery
that lightning was magnetic. However, this seems to have been beyond the thinking of the
mechanical fashion. The incident shows how the experimental method often fails. The result was
interpreted as proof of the mechanical nature of magnetism, not the magnetic nature of lightning.
Another missed opportunity was the failure to follow up on the failed attempts to measure the
variation in 1666. There were efforts urged to perform systematic measurements over a long
period of time. but these were not implemented. The pursuit of science at this time was not
sufficiently organized and methodological to encourage such an enterprise. The Royal Society
seemed to be organized to achieve short term goals, and long term scientific programs of
discovery were not seen as valuable efforts.
A major area of decline was experienced in the practice of magnetic measurement. There is no
evidence of magnetic work using Gilbert’s techniques with the compass needle. The use of iron
filings however, was widely adopted. But, there was no systematic mapping of the field using the
compass or short wires. This is the basis for asserting the decline of magnetic science during the
period. The only measurements that were performed were done using balance scales, as used by
Hooke to perform measures of magnetic force.
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