Amazon.com description: Product Description: "[...]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 magnet held underneath. We are told by other writers that images of the gods and goddesses were suspended in the air by lodestone in the ceilings of the temples of Diana of Ephesus, of Serapis at Alexandria, and others. It is surprising, however, that neither the Greeks nor Romans, with all their philosophy, would seem to have discovered its directive property. During the dark ages pieces of Lodestone mounted as magnets were employed in the "black arts." A small natural magnet of this kind is shown in figure 25, where L is the stone shod with two iron "pole-pieces," which are joined by a "keeper" A or separable bridge of iron carrying a hook for supporting weights.[...]".