pointing out the north and south direction was discovered by
dropping a light piece of the stone, if not a sewing needle made
of it, on the surface of still water. At all events, we read in
Pere Du Halde's Description de la Chine, that sometime in or about
the year 2635 B.C. the great Emperor Hoang-ti, having lost his way
in a fog whilst pursuing the rebellious Prince Tchiyeou on the
plains of Tchou-lou, constructed a chariot which showed the
cardinal points, thus enabling him to overtake and put the prince
to death.

A magnetic car preceded the Emperors of China in ceremonies of
state during the fourth century of our era. It contained a genius
in a feather dress who pointed to the south, and was doubtless
moved by a magnet floating in water or turning on a pivot. This
rude appliance was afterwards refined into the needle compass for
guiding mariners on the sea, and assisting the professors of feng-
shui or geomancy in their magic rites.

Magnetite was also found at Heraclea in Lydia, and at Magnesium on
the Meander or Magnesium at Sipylos, all in Asia Minor. It was
called the "Heraclean Stone" by the people, but came at length to
bear the name of "Magnet" after the city of Magnesia or the
mythical shepherd Magnes, who was said to have discovered it by
the attraction of his iron crook.

The ancients knew that it had the power of communicating its
attractive property to iron, for we read in Plato's "Ion" that a
number of iron rings can be supported in a chain by the Heraclean
Stone. Lucretius also describes an experiment in which iron
filings are made to rise up and "rave" in a brass basin by a