Note x — Chapter IX · [a] (continued 2)

Boucher, the French translator of Il Consolato del Mare, says that Edrissi, a Saracen geographer who lived about 1100, gives an account, though in a confused manner, of the polarity of the magnet. t. ii. p. 280. However, the lines of Guiot de Provins are decisive. These are quoted in Hist. Littéraire de la France, t. ix. p. 199; Mém. de l'Acad. des Inscript. t. xxi. p. 192; and several other works. Guinizzelli has the following passage, in a canzone quoted by Ginguené, Hist. Littéraire de l'Italie, t. i. p. 413:—

We cannot be diverted, by the nonsensical theory these lines contain, from perceiving the positive testimony of the last verse to the poet's knowledge of the polarity of the magnet. But if any doubt could remain, Tiraboschi (t. iv. p. 171) has fully established, from a series of passages, that this phenomenon was well known in the thirteenth century; and puts an end altogether to the pretensions of Flavio Gioja, if such a person, ever existed. See also Macpherson's Annals, p. 364 and 418. It is provoking to find an historian like Robertson asserting, without hesitation, that this citizen of Amalfi was the inventor of the compass, and thus accrediting an error which had already been detected.

It is a singular circumstance, and only to be explained by the obstinacy with which men are apt to reject improvement, that the magnetic needle was not generally adopted in navigation till very long after the discovery of its properties, and even after their peculiar importance had been perceived. The writers of the thirteenth century, who mention the polarity of the needle, mention also its use in navigation; yet Capmany has found no distinct proof of its employment till 1403, and does not believe that it was frequently on board Mediterranean ships at the latter part of the preceding age. Memorias Historicas, t. iii. p. 70. Perhaps however he has inferred too much from his negative proof; and this subject seems open to further inquiry.