y of the
Dip of the magnetic needle, and of his investigation of it by means of the
Dipping-needle, which he invented. He was a compassmaker of the port of
London, and lived at Limehouse.

[27] PAGE 5, LINE 32. Page 5, line 40. _Franciscus Maurolycus_.--The work
to which the myth of the magnetic mountains is thus credited is, _D.
Francisci Abbatis Messanensis Opuscula Mathematica_, etc. (Venet, MDLXXV,
p. 122a). "Sed cur sagitta, vel obelus a vero Septentrione, quandoque ad
dextram, {12} quandoque ad sinistram declinat? An quia sagitta, sicut
magnes (cuius est simia) non verum Septentrionem, sed insulam quandam (quam
Olaus Magnus Gothus in sua geographia vocat insulam magnetum) semper ex
natura inspicere cogitur?"

[28] PAGE 5, LINE 35. Page 5, line 43. _Olaus Magnus_.--The famous
Archbishop of Upsala, who wrote the history of the northern nations
(_Historia de Gentibus Septentrionalibus_), of which the best edition,
illustrated with many woodcuts, appeared in Rome in 1555. An English
edition entitled _A Compendious History of the Goths, Swedes, and Vandals,
and Other Northern Nations_ was printed in London in 1658; but it is much
abbreviated and has none of the quaint woodcuts. The reference on p. 5
appears to be to the following passage on p. 409 (ed. 1555). "Demum in
suppolaribus insulis magnetum montes reperiuntur, quorum fragmentis ligna
fagina certo tempore applicata, in saxeam duritiem, et vim attractivam
convertuntur," or the following on p. 89: "Magnetes enim in extremo
Septentrionis veluti montes, unde nautica directio constat, reperiuntur:
quorum etiam magnetum tam vehemens est operatio, ut certis lignis fagineis
conjuncti, ea vertunt in sui duritiem, & naturam attractivam." On p. 343 is
a woodcut depicting the penalties inflicted by the naval laws upon any one
who should maliciously tamper with the compass or the loadstone, "qui
malitiose nauticum gnomonem, aut compassum, & praecipue portionem magnetis,
unde omnium directio dependet, falsaverit." He was to be pinned to the mast
by a dagger thrust through his hand. It will be noted that the ships
carried both a compass, and a piece of loadstone wherewith to stroke the
needle.

There is in the Basel edition of this work, 1567, a note _ad lectorem_, on
the margin of Carta 16a, as follows:

"Insula 30 milliarium in longitud. & latitud. Polo arctico subjecta.

"Vltra quam directorium nauticum bossolo dic[~u] uires amittit: propterea
quod ilia insula plena es