Note 26 — Chapter III · THAT PRESCIENCE IS USEFUL

Whalley, in translating this chapter, makes the following remark on this mention of the magnet: “However much later it was that the loadstone became known in Europe, what is mentioned of it in this chapter makes it evident that it was known in Ægypt, where Ptolemy lived, in his time.”—That worthy translator forgot (if indeed he ever knew) that the loadstone’s property of attracting iron was known to Thales, and commented on by Plato and Aristotle, all of whom lived some centuries, more or less, before Ptolemy. It is its polarity that was not known until the 11th or 12th century; and the French say that the earliest notice of that polarity is found in a poem of Guyot of Provence, who was at the Emperor Frederick’s Court at Mentz in 1181.—See the French Encyclopædia, &c.