''
But while these practically-minded engineers were improving
upon their rattling ``heat engines,'' a group of ``pure''
scientists (men who devote fourteen hours of each day to the
study of those ``theoretical'' scientific phenomena without which
no mechanical progress would be possible) were following a
new scent which promised to lead them into the most secret and
hidden domains of Nature.
Two thousand years ago, a number of Greek and Roman
philosophers (notably Thales of Miletus and Pliny who was
killed while trying to study the eruption of Vesuvius of the
year 79 when Pompeii and Herculaneum were buried beneath
the ashes) had noticed the strange antics of bits of straw and of
feather which were held near a piece of amber which was being
rubbed with a bit of wool. The schoolmen of the Middle Ages
had not been interested in this mysterious ``electric'' power.
But immediately after the Renaissance, William Gilbert, the
private physician of Queen Elizabeth, wrote his famous treatise
on the character and behaviour of Magnets. During the
Thirty Years War Otto von Guericke, the burgomaster of
Magdeburg and the inventor of the air-pump, constructed the
first electrical machine. During the next century a large number
of scientists devoted themselves to the study of electricity.
Not less than three professors invented the famous Leyden
Jar in the year 1795.
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