in iron plates touched by loadstone, 84.

in iron sphere, 85.

how, in iron, 123, 139, 212.

in bracket in tower of St. Augustine's Church, Rimini, 141.

similar at ends of rod touched in middle, 84, 129.

by percussion, 139.

through interposed matter, 67.

not in bodies other than magnetick, 142.

aequator separates two kinds of, 79.

possessed by the earth, as a "Cause," 117.

change of, through change of mass, 72.

definition of, *vj.

described, 119, 120, 121.

destroyed by heat, 66, 93, 124.

earth produces it in loadstone and iron, 42, 140, 211, 212.

excited through greater distances in iron than in air, 104.

exists in all shapes of loadstone, 76.

helps the earth to keep its orbit, 224.

inhaerent in wrought iron, 31, 115.

as a magnetick motion, 46.

mutation of, 120, 137.

magnitude of earth prevents variation of, 163, 164.

none acquired by iron rubbed on aequator of terrella, 148.

not affected by position of loadstone, 144.

of one loadstone as affected by another, 69, 138.

opposite, acquired by iron touched by loadstone, 115, 125, 129.

parts having same repel, 122, 133.

pole of, where last contact is, 149.

strengthened in versoria, 147-150.

strength of, decreases at once in both poles, 146.

Villa nova, Arnaldus de, 2, 7.

vincentina, the, 48.

Vincent's Rock, gem of, 54.

Weather affects electricks, 48, 53, 55, 56.

weighing the magnetick force, 108.

Wright, Edward, his prefatory address, *iij _bis_, 7.

wrought iron is magnetick, 29, 139.

Youth preserved by loadstone, 32.

Zeilam, the king of, 32.

Zimiri, 11.

Zoroaster, 209.

{247} THIS TREATISE BY WILLIAM GILBERT, OF COLCHESTER, PHYSICIAN OF LONDON, ON THE MAGNET, WAS FIRST PUBLISHT IN THE LATIN TONGUE IN LONDON IN THE YEAR OF OUR LORD M.D.C.; THIS ENGLISH TRANSLATION, WHICH WAS COMPLETED IN THE YEAR M.C.M., IS PRINTED FOR THE GILBERT CLUB, TO THE NUMBER OF TWO HUNDRED AND FIFTY COPIES, BY CHARLES WHITTINGHAM AND COMPANY, AT THE CHISWICK PRESS, TOOKS COURT, CHANCERY LANE, LONDON.

[Illustration]

NOTES

ON THE

DE MAGNETE

OF

DR. WILLIAM GILBERT

[Illustration]

PRIVATELY PRINTED

LONDON MCMI

"For out of olde feldes, as men seith, Cometh al this newe corn fro yeer to yere; And out of olde bokes, in good feith, Cometh al this newe science that men lere."

--_Chaucer._

"I finde that you have vsed in this your tr[=a]slation greate art, knowledge, and discretion. For walking as it were in golden fetters (as al Translators doe) you notwithstanding so warilie follow your Auctor, that where he trippeth you hold him vp, and where he goeth out of the way, you better direct his foote. You haue not only with the Bee sucked out the best iuyce from so sweete a flower, but with the Silke-worme as it were wouen out of your owne bowels, the finest silke; & that which is more, not rude & raw silke, but finely died with the fresh colour of your owne Art, Invention, and Practise. If these Adamantes draw you not to effect this which you haue so happilie begunne: then let these spurres driue you forward: viz. Your owne promise, the expectation of your friends, the losse of some credit if you should steppe backe, the profit which your labours may yeeld to many, the earnest desire which you yourselfe haue to reviue this Arte, and the vndoubted acceptation of your paines, if you performe the same."--(Prefatory epistle of John Case, D. of Physicke, printed in R. Haydocke's translation of _The Artes of Curious Painting_, of Lomatius, Oxford, 1598.)

"This booke is not for every rude and unconnynge man to see, but for clerkys and very gentylmen that understand gentylness and scyence."--_Caxton._

CHISWICK PRESS: CHARLES WHITTINGHAM AND CO.

TOOKS COURT, CHANCERY LANE, LONDON.

{ij}

[Illustration]

BIBLIOGRAPHY OF _DE MAGNETE_.

I. (THE LONDON FOLIO OF 1600.) _Fol. *j. title_ GVILIELMI GIL berti colcestren sis, medici londi- nensis, DE MAGNETE, MAGNETI- cisqve corporibvs, et de mag- no magnete tellure; Physiologia noua, plurimis & argumentis, & expe- rimentis demonstrata. _Printer's Mark_ Londini excudebat Petrvs Short anno MDC. _*j verso_ Gilbert's coat of arms. _*ij_ Ad Lectorem _*iij verso_ Ad gravissimvm doctissimvmqve ... _*vj_ Verborum quorundam interpretatio. _*vj verso_ Index capitum. p.

1. GVILIELMI GILBERTI DE MAGNETE, LIB. I. p. 240. FINIS. Errata.

Without any colophon, printer's Mark, or date at end. _Folio. 8 ll. of preliminary matter._ ABCDEFGHIKLMNOPQRSTV, _all ternions, making 120 numbered leaves. One blank leaf at front and one at end. Page 114 at end of Liber II. blank. A folded woodcut plate inserted between p. 200 and p. 201.

Woodcut initials, headlines and diagrams. All known copies except one have ink corrections in several pages, particularly pp. 11, 22, 47._

II. (THE STETTIN QUARTO OF 1628.) _Four preliminary unnumbered leaves, viz._ (1) _Bastard title_ GULIELMI GILBERTI Tractatus DE MAGNETE _verso_ blank; (2) _Engraved title._ TRACTATVS Siue PHYSIOLOGIA NOVA DE MAGNETE, MAGNETICISQVE CORPO- RIBVS ET MAGNO MAGNETE tellure Sex libris comprehensus Guilielmo Gilberto Colcestrensi, Medico Londinensi ... Omnia nunc diligenter recognita & emen- datius quam ante in lucem edita, aucta & figu- ris illustrata opera & studio Wolfgangi LOCHMANS I.U.D. & Mathemati: Ad calcem libri adjunctus est Index Capi- tum Rerum et Verborum locupletissimus EXCVSVS SEDINI Typis Gotzianis Sumptibus _Ioh: Hallervordij._ Anno MDC.XXVIII _verso_ blank; (3) Praefatio; (4) Amicorum Acclamationes (verses) _verso_ blank. _Sig._ A Ad Lectorem Candidum. _Sig._ A2 _verso_ Ad Gravissimum Doctissimum[=q] Virum.

_Sig._ B2 Verborum quorundam interpretatio. _Verso_ blank, followed by twelve engraved plates numbered I. to XII. _Sig._ B3 is numbered as p. 1, and begins GVILIELMI GILBERTI DE MAGNETE. LIBER I. _Sig._ C _begins as p. 5_; _Sig._ D as p. 13; and so forth. The collation therefore is: 4 ll.

unnumbered, ABCDEFGHIKLMNOPQRSTVXYZAaBbCcDdEeFfGgHhIiKkLlMm, _all fours.

Pagination ends on_ p. 232, _which has Sig._ H_3 _in error for_ Hh_3, _being the end of the text. Verso of_ Hh_3 blank. Index capitum _begins fol._ [Hh_4] _and_ with Index Verborum _continues to verso of_ Mm_3. _Last leaf_ [Mm_4] _contains Errata, and instructions to binder to place plates: verso_ blank. _Quarto. Woodcut initials and diagrams. Without any colophon, printer's Mark, or date at end._ In some copies the engraved title differs, having the words _Ioh: Hallervordij._ replaced by the word _Authoris_.

{iij} III. (THE STETTIN QUARTO OF 1633.) _Four preliminary unnumbered leaves_, viz., (1) _title._ Tractatus, sive Physiologia Nova de MAGNETE, Magneticisq; corporibus & magno Magnate tellure, sex libris comprehensus, a GUILIELMO GILBERTO Colce- strensi, Medico Londinensi. ... Omnia nunc diligenter recognita, & emendatius quam ante in lucem edita, aucta & figuris illustrata, opera & studio D. WOLFGANGI LOCHMANS, I.U.D. & Mathematici. Ad calcem libri adiunctus est Index capitum, Rerum & Verborum locupletissimus, qui in priore aeditione desiderabatur SEDINI, Typis GOTZIANIS. ANNO M.DC. XXXII. _verso_ blank; (2) Praefatio; (3) Amicorum acclamationes (verses) _verso_ Claudianus de Magnete (verses); (4) _ibid._ _Sig._ A Ad Lectorem Candidum. _Sig._ A2 _verso_ Ad Gravissimum Doctissimumq. Virum. _Sig._ B2 Verborum quorundam interpretatio; _verso_ blank. _Sig._ B3 is numbered as p. 1, and begins GVILIELMI GILBERTI DE MAGNETE. LIBER I. _Sig._ C begins as p. 5; _Sig._ D as p. 13; and so forth. The Collation therefore is: 4 _ll._ unnumbered, A _to_ Mm, _all fours_. Pagination _ends on p. 232, which bears Sig._ H3 _in error for_ Hh3. _Verso of Sig._ Hh3. Errata. Index capitum _begins_ Hh4, _and with_ Index Verborum _extends to verso_ of Mm3. _The last leaf_ [Mm4]

_bears the Instructions to binder, with verso_ blank. _There is no colophon, printer's Mark, or date at end. Quarto. Woodcut initials, and diagrams. Twelve etched plates of various sizes inserted._