n Augsburg, 1558. See also Bertelli in
Boncompagni's _Bollettino di bibliografia_, t. i., or S. P. Thompson in
_Proc. British Academy_, vol. ii.) Of this work twenty-eight MSS. exist;
seven of them being at Oxford. The first part of the epistle deals
generally with magnetic attractions and repulsions, with the polarity of
the stone, and with the supposed influence of the poles of the heavens
upon the poles of the stone. In the second part Peregrinus describes
first an improved floating compass with fiducial line, a circle
graduated with 90 degrees to each quadrant, and provided with movable
sights for taking bearings. He then describes a new compass with a
needle thrust through a pivoted axis, placed in a box with transparent
cover, cross index of brass or silver, divided circle, and an external
"rule" or alhidade provided with a pair of sights. In the Leiden MS. of
this work, which for long was erroneously ascribed to one Peter Adsiger,
is a spurious passage, long believed to mention the variation of the
compass.

Prior to this clear description of a pivoted compass by Peregrinus in
1269, the Italian sailors had used the floating magnet, probably
introduced into this region of the Mediterranean by traders belonging to
the port of Amalfi, as commemorated in the line of the poet Panormita:--

"Prima dedit nautis usum magnetis Amalphis."

This opinion is supported by the historian Flavius Blondus in his
_Italia illustrata_, written about 1450, who adds that its certain
origin is unknown. In 1511 Baptista Pio in his _Commentary_ repeats the
opinion as to the invention of the use of the magnet at Amalfi as
related by Flavius. Gyraldus, writing in 1540 (_Libellus de re
nautica_), misunderstanding this reference, declared that this
observation of the direction of the magnet to the poles had been handed
down as discovered "by a certain Flavius." From this passage arose a
legend, which took shape only in the 17th century, that the compass was
invented in the year 1302 by a person to whom was given the fictitious
name of Flavio Gioja, of Amalfi.

From the above it will have been evident that, as Barlowe remarks
concerning the compass, "the lame tale of one Flavius at Amelphus, in
the kingdome of Naples, for to have devised it, is of very slender
probabilitie"; and as regards the assertion of Dr Gilbert, of Colchester
(_De magnete_, p. 4, 1600), that Marco Polo introduced the compass into
Italy from the East in 1260,[4] we