Aldrovandi in the _Musæum Metallicum_ (Bonon., 1648, p. 554) gives another version of the fable:
"Nonnulli, animadversa hac Magnetis natura, scripserunt naves, quibus in Calecutanam regionem navigatur, clavis ferreis non figi, ob magneticorum frequentiam scopulorum, quoniam facilè dissolverentur. Sed Garzias in Historia Aromatum id fabulosum esse tradidit: quandoquidem plures naues Calecutanæ regionis, & illius tractus, ferreis clauis iunctas obseruauit: immò addidit naues in insulis Maldiuis ligneis quidem clauis copulari, non quia à Magnete sibi metuant, sed quoniam ferri inopia laborant."
According to Aldrovandi (p. 563, _op. citat._) the magnetic mountains are stated by Sir John Mandeville to be in the region of Pontus.
Lipenius in his _Navigatio Salomonis Ophritica illustrata_ (Witteb., 1660), which is a mine of curious learning, in discussing the magnetic mountains quotes the reply of Socrates to the inquirer who asked him as to what went on in the infernal regions, saying that he had never been there nor had he ever met any one who had returned thence.
The loadstone rock figures in several early charts. In Nordenskiöld's _Facsimile Atlas_ (Stockholm, 1889) is given a copy of the Map of Johan Ruysch from an edition of Ptolemy, publisht in Rome in 1508, which shows four islands within the ice-bound Arctic regions. South of these islands and at the east of the coast of Greenland is the inscription: _Hic compassus navium non tenet, nec naves quæ ferrum tenent revertere valent._ To which (on p. 63) Nordenskiöld adds the comment: _Sagan on magnetberg, som skulle draga till sig fartyg förande jern, är gamal._ And he recalls the reference of Ptolemy to the magnetic rocks in the Manioles. A second inscription is added to Ruysch's map in the ornamental margin that borders the Arctic islands. _Legere est in libro de inventione fortunati sub polo arctico rupem esse excelsam ex lapide magnete 33 miliarium germanorum ambitu._ This refers to a matter recorded in Hakluyt's _Principall Navigations_ (Lond., 1589, p. 249), namely: "A Testimonie of the learned Mathematician, maister John Dee, { 14} touching the foresaid voyage of Nicholas de Linna. Anno 1360 a frier of Oxford, being a good Astronomer, went in companie with others to the most Northren islands of the world, and there leaving his company together, he travelled alone, and purposely described all the Northern islands, with the indrawing seas: and the record thereof at his return he delivered to the king of England. The name of which booke is _Inventio Fortunata_ (_aliter fortunæ_) _qui liber incipit a gradu 54 usq. ad polum_."