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_." The situation of the alleged loadstone rock is thus described by T. Blundevile in his _Exercises_ in the chapter entitled _A plaine and full description of Peter Plancius his vniuersall Map, seruing both for sea and land, and by him lately put foorth in the yeare of our Lord, 1592_.... Written in our mother tongue by M. Blundeuill, Anno Domini 1594. The passage is quoted from p. 253 of the third edition (1606):