Gilbert's complaint of the evil practice of setting the needles obliquely beneath the card, with the intention of allowing for the variation, is an echo of a similar complaint in Norman's Newe Attractiue. In chapter x. of this work Norman thus enumerates the different kinds of compasses:
"Of these common Sayling Compasses, I find heere (in Europa) five sundry sortes or sets. The first is of Levant, made in Scicile, Genoüa, and Venice: And these are all (for the most parte) made Meridionally, with the Wyers directlye sette under the South, and North of the Compasse: And therefore, duely shewing the poynt Respective, in all places, as the bare Needle. And by this Compasse are the Plats made, for the most part of all the Levants Seas.
"Secondly, there are made in Danske, in the Sound of Denmarke, and in Flanders, that have the Wyers set at 3 quarters of a point to the Eastwards of the North of the compasse, and also some at a whole point: and by these Compasses they make both the Plats and Rutters for the Sound.
"Thirdly, there hath beene made in this Countrey particulary, for Saint Nicholas and Ruscia, Compasses set at 3 seconds of a point, and the first Plats of that Discoverie were made by this Compasse.
"Fourthly the Compasse made at Sevill, Lisbone, Rochell, Bourdeaux, Roan, and heere in England, are moste commonly set at halfe a point: And by this Compasse are the Plats of the East and West Indies made for their Pylotes, and also for our Coastes neere hereby, as France, Spayne, Portugall, and England: and therefore best of these Nations to bee used, because it is the most common sorte that is generally used in these Coastes."
Bessard (op. citat., pages 22 and 48) gives cuts of compasses showing the needle displaced one rumbe to the East.
Gallucci, in his Ratio fabricandi horaria mobilia et permanentia cum magnetica acu (Venet., 1596), describes the needle as inclined 10 degrees from the south toward the south-west.
The frontispiece of the work of Pedro Nuñez, Instrumenta Artis Navigandi, Basil., 1592, depicts a compass with the lily set one point to the east.
Reibelt, De Physicis et Pragmaticis Magnetis Mysteriis (Herbipolis, 1731), depicts the compass with the needle set about 12 degrees to the East of North. See also Fournier, Hydrographie (Paris 1667); De Lanis, Magisterium Natvræ et Artis (Brixiæ, 1684); Milliet Deschales, Cursus seu Mundus
Mathematicus (Lugd., 1674). Both the latter works give pictures of the compass-cards as used in South Europe, and in North Europe, and of the various known shapes of needles.
[227] Page 168, line 29. Page 168, line 33. Directio igitur inualidior est propè polos. Here as in many passages direction means the force which directs. A similar usage prevails with the nouns variation and declination, meaning frequently the force causing variation or declination respectively.
Page 172, line 13. perquirere. The edition of 1633 reads perquirero, in error.
[228] Page 172, line 29. Page 172, line 33. Ad pyxidis nauticæ veræ & meridionalis formam ... fiat instrumentum.—An excellent form of portable meridian compass, provided with sights for taking astronomical observations, is described by Barlowe (The Navigators Supply, London, 1597), and is depicted in an etched engraving. An identical engraving is repeated in Dudley's Arcano del Mare (Firenze, 1646). Gilbert's new instrument was considerably larger.