Note 520 — Chapter I
Reading edition
Cp. Pignotti, Hist. of Tuscany, Eng. trans. 1823, iii, 256; Hallam, Middle Ages, 11th ed. iii, 328, 332. It is clear that the polarity of the magnet was known long before the practical use of it in the compass.
Reading edition
Cp. Pignotti, Hist. of Tuscany, Eng. trans. 1823, iii, 256; Hallam, Middle Ages, 11th ed. iii, 328, 332. It is clear that the polarity of the magnet was known long before the practical use of it in the compass.