On the Magnet, by William Gilbert

headpiece

William Gilbert

On the Loadstone, Bk. I.

Chap. i.

Ancient and Modern Writings on the Loadstone, with certain matters of mention only, various opinions, & vanities.

A t an early period, while philosophy lay as yet rude and uncultivated in the mists of error and ignorance, few were the virtues and properties of things that were known and clearly perceived: there was a bristling forest of plants and herbs, things metallick were hidden, and the knowledge of stones was unheeded. But no sooner had the talents and toils of many brought to light certain commodities necessary for the use and safety of men, and handed them on to others (while at the same time reason and experience had added a larger hope), than a thorough examination began to be made of forests and fields, hills and heights; of seas too, and the depths of the waters, of the bowels of the earth's body; and all things began to be looked into. And at length by good luck the magnet-stone was discovered in iron lodes, probably by smelters of iron or diggers of metals. This, on being handled by metal folk, quickly displayed that powerful and strong attraction for iron, a virtue not latent and obscure, but easily proved by all, and highly praised and commended. And in after time when it had emerged, as it were out of darkness and deep dungeons, and had become dignified of men on account of its strong and amazing attraction for iron, many philosophers as well as physicians of ancient days discoursed of it, in short celebrated, as it were, its memory only; as for instance Plato in the Io2, Aristotle in the De Anima3, in Book I. only, Theophrastus the Lesbian, Dioscorides, C. Plinius Secundus, and Julius Solinus4. As handed down by them the loadstone merely attracted iron, the rest of its virtues were all undiscovered. But that the story of the loadstone might not appear too bare and too brief, to this singular and sole known quality there were added certain figments and falsehoods, which in the earliest times, no less than nowadays, used to be put forth by raw smatterers and copyists to be swallowed of men. As for instance, that if a loadstone be anointed with garlick, or if a diamond be near, it does not attract iron5. Tales of this sort occur in Pliny, and in Ptolemy's Quadripartitum; and the errors have been sedulously propagated, and have gained ground (like ill weeds that grow apace) coming down even to our own day, through the writings of a host of men, who, to fill put their volumes to a proper bulk, write and copy out pages upon pages on this, that, and the other subject, of which they knew almost nothing for certain of their own experience. Such fables of the loadstone even Georgius Agricola himself, most distinguished in letters, relying on the writings of others, has embodied as actual history in his books De Natura Fossilium. Galen noted its medicinal power in the ninth book of his De Simplicium Medicamentorum Facultatibus, and its natural property of attracting iron in the first book of De Naturalibus Facultatibus; but he failed to recognize the cause, as Dioscorides before him, nor made further inquiry. But his commentator Matthiolus repeats the story of the garlick and the diamond, and moreover introduces Mahomet's shrine vaulted with loadstones6, and writes that, by the exhibition of this (with the iron coffin hanging in the air) as a divine miracle, the public were imposed upon. But this is known by travellers to be false. Yet Pliny relates that Chinocrates the architect had commenced to roof over the temple of Arsinoe at Alexandria with magnet-stone7, that her statue of iron placed therein might appear to hang in space. His own death, however, intervened, and also that of Ptolemy, who had ordered it to be made in honour of his sister. Very little was written by the ancients as to the causes of attraction of iron; by Lucretius and others there are some short notices; others only make slight and meagre mention of the attraction of iron: all of these are censured by Cardan for being so careless and negligent in a matter of such importance and in so wide a field of philosophizing; and for not supplying an ampler notion of it and a more perfect philosophy: and yet, beyond certain received opinions and ideas borrowed from others and ill-founded conjectures, he has not himself any more than they delivered to posterity in all his bulky works any contribution to the subject worthy of a philosopher. Of modern writers some set forth its virtue in medicine only, as 8Antonius Musa Brasavolus, Baptista Montanus, Amatus Lusitanus, as before them Oribasius in his thirteenth chapter De Facultate Metallicorum, Aetius Amidenus, Avicenna, Serapio Mauritanus, Hali Abbas, Santes de Ardoynis, Petrus Apponensis, Marcellus9, Arnaldus. Bare mention is made of certain points relating to the loadstone in very few words by Marbodeus Callus, Albertus, Matthæus Silvaticus, Hermolaus Barbarus, Camillus Leonhardus, Cornelius Agrippa, Fallopius, Johannes Langius, Cardinal Cusan, Hannibal Rosetius Calaber; by all of whom the subject is treated very negligently, while they merely repeat other people's fictions and ravings. Matthiolus compares the alluring powers of the loadstone which pass through iron materials, with the mischief of the torpedo, whose venom passes through bodies and spreads imperceptibly; Guilielmus Pateanus in his Ratio Purgantium Medicamentorum discusses the loadstone briefly and learnedly. Thomas Erastus10, knowing little of magnetical nature, finds in the loadstone weak arguments against Paracelsus; Georgius Agricola, like Encelius11 and other metallurgists, merely states the facts; Alexander Aphrodiseus in his Problemata considers the question of the loadstone inexplicable; Lucretius Carus, the poet of the Epicurean school, considers that an attraction is brought about in this way: that as from all things there is an efflux of very minute bodies, so from the iron atoms flow into the space emptied by the elements of the loadstone, between the iron and the loadstone, and that as soon as they have begun to stream towards the loadstone, the iron follows, its corpuscles being entangled. To much the same effect Johannes Costæus adduces a passage from Plutarch; Thomas Aquinas12, writing briefly on the loadstone in Chapter VII. of his Physica, touches not amiss on its nature, and with his divine and clear intellect would have published much more, had he been conversant with magnetick experiments. Plato thinks the virtue divine. But when three or four hundred years afterwards, the magnetick movement to North and South was discovered or again recognized by men, many learned men attempted, each according to the bent of his own mind, either by wonder and praise, or by some sort of reasonings, to throw light upon a virtue so notable, and so needful for the use of mankind. Of more modern authors a great number have striven to show what is the cause of this direction and movement to North and South, and to understand this great miracle of nature, and to disclose it to others: but they have lost both their oil and their pains; for, not being practised in the subjects of nature, and being misled by certain false physical systems, they adopted as theirs, from books only, without magnetical experiments, certain inferences based on vain opinions, and many things that are not, dreaming old wives' tales. Marsilius Ficinus ruminates over the ancient opinions, and in order to show the reason of the direction seeks the cause in the heavenly constellation of the Bear, supposing the virtue of the Bear to prevail in the stone and to be transferred to the iron. Paracelsus asserted that there are stars, endowed with the power of the loadstone, which attract to themselves iron. Levinus Lemnius describes and praises the compass13, and infers its antiquity on certain grounds; he does not divulge the hidden miracle which he propounds. In the kingdom of Naples the Amalfians were the first (so it is said) to construct the mariners' compass: and as Flavius Blondus says the Amalfians14 boast, not without reason, that they were taught by a certain citizen, Johannes Goia, in the year thirteen hundred after the birth of Christ. That town is situated in the kingdom of Naples not far from Salerno, near the promontory of Minerva; and Charles V. bestowed that principality on Andrea Doria, that great Admiral, on account of his signal naval services. Indeed it is plain that no invention of man's device has ever done more for mankind than the compass: some notwithstanding consider that it was discovered by others previously and used in navigation, judging from ancient writings and certain arguments and conjectures. The knowledge of the little mariners' compass seems to have been brought into Italy by Paolo, the Venetian15, who learned the art of the compass in the Chinas about the year MCCLX.; yet I do not wish the Amalfians to be deprived of an honour so great as that of having first made the construction common in the Mediterranean Sea. Goropius16 attributes the discovery to the Cimbri or Teutons, forsooth because the names of the thirty-two winds inscribed on the compass are pronounced in the German tongue by all ship-masters, whether they be French, British, or Spaniards; but the Italians describe them in their own vernacular. Some think that Solomon, king of Judæa, was acquaint with the use of the mariners' compass, and made it known to his ship-masters in the long voyages when they brought back such a power of gold from the West Indies: whence also, from the Hebrew word Parvaim17, Arias Montanus maintains that the gold-abounding regions of Peru are named But it is more likely to have come from the coast of lower Æthiopia, from the region of Cephala, as others relate. Yet that account seems to be less true, inasmuch as the Phœnicians, on the frontier of Judæa, who were most skilled in navigation in former ages (a people whose talents, work, and counsel Solomon made use of in constructing ships and in the actual expeditions, as well as in other operations), were ignorant of magnetick aid, the art of the mariners' compass: For had it been in use amongst them, without doubt the Greeks and also Italians and all barbarians would have understood a thing so necessary and made famous by common use; nor could matters of much repute, very easily known, and so highly requisite ever have perished in oblivion; but either the learning would have been handed down to posterity, or some memorial of it would be extant in writing. Sebastian Cabot was the first to discover that the magnetick iron varied18. Gonzalus Oviedus19 is the first to write, as he does in the Historia, that in the south of the Azores it does not vary. Fernelius in his book De Abditis Rerum Causis says that in the loadstone there is a hidden and abstruse cause, elsewhere calling it celestial; and he brings forth nothing but the unknown by means of what is still more unknown. For clumsy, and meagre, and pointless is his inquiry into hidden causes. The ingenious Fracastorio, a distinguished philosopher, in seeking the reason for the direction of the loadstone, feigns Hyperborean magnetick mountains attracting magnetical things of iron: this view, which has found acceptance in part by others, is followed by many authors and finds a place not in their writings only, but in geographical tables, marine charts, and maps of the globe: dreaming, as they do, of magnetick poles and huge rocks, different from the poles of the earth. More than two hundred years earlier than Fracastorio there exists a little work, fairly learned for the time, going under the name of one Peter Peregrinus20, which some consider to have originated from the views of Roger Bacon, the Englishman of Oxford: In which book causes for magnetick direction are sought from the poles of the heaven and from the heaven itself. From this Peter Peregrinus, Johannes Taisnier of Hainault21 extracted materials for a little book, and published it as new. Cardan talks much of the rising of the star in the tail of the Greater Bear, and has attributed to its rising the cause of the variation: supposing that the variation is always the same, from the rising of the star. But the difference of the variation according to the change of position, and the changes which occur in many places, and are even irregular in southern regions, preclude the influence of one particular star at its northern rising. The College of Coimbra22 seeks the cause in some part of the heaven near the pole: Scaliger in section CXXXI. of his Exercitationes on Cardan suggests a heavenly cause unknown to himself, and terrestrial loadstones nowhere yet discovered. A cause not due to those sideritic mountains named above, but to that power which fashioned them, namely that portion of the heaven which overhangs that northern point. This view is garnished with a wealth of words by that erudite man, and crowned with many marginal subtilities; but with reasonings not so subtile. Martin Cortes23 considers that there is a place of attraction beyond the poles, which he judges to be the moving heavens. One Bessardus24, a Frenchman, with no less folly notes the pole of the zodiack. Jacobus Severtius25, of Paris, while quoting a few points, fashions new errors as to loadstones of different parts of the earth being different in direction: and also as to there being eastern and western parts of the loadstone. Robert Norman26, an Englishman, fixes a point and region respective, not attractive; to which the magnetical iron is collimated, but is not itself attracted. Franciscus Maurolycus27 treats of a few problems on the loadstone, taking the trite views of others, and avers that the variation is due to a certain magnetical island mentioned by Olaus Magnus28. Josephus Acosta29, though quite ignorant about the loadstone, nevertheless pours forth vapid talk upon the loadstone. Livio Sanuto30 in his Italian Geographia, discusses at length the question whether the prime magnetick meridian and the magnetick poles are in the heavens or in the earth; also about an instrument for finding the longitude: but through not understanding magnetical nature, he raises nothing but errors and mists in that so important notion. Fortunius Affaytatus31 philosophizes foolishly enough on the attraction of iron, and its turning to the poles. Most recently, Baptista Porta32, no ordinary philosopher, in his Magia Naturalis, has made the seventh book a custodian and distributor of the marvels of the loadstone; but little did he know or ever see of magnetick motions; and some things that he noted of the powers which it manifested, either learned by him from the Reverend Maestro Paolo, the Venetian33, or evolved from his own vigils, were not so well discovered or observed; but abound in utterly false experiments, as will be clear in due place: still I deem him worthy of high praise for having attempted so great a subject (as he has done with sufficient success and no mean result in many other instances), and for having given occasion for further research. All these philosophizers of a previous age, philosophizing about attraction from a few vague and untrustworthy experiments, drawing their arguments from the hidden causes of things; and then, seeking for the causes of magnetick directions in a quarter of the heavens, in the poles, the stars, constellations, or in mountains, or rocks, space, atoms, attractive or respective points beyond the heavens, and other such unproven paradoxes, are whole horizons wrong, and wander about blindly. And as yet we have not set ourselves to overthrow by argument those errors and impotent reasonings of theirs, nor many other fables told about the loadstone, nor the superstitions of impostors and fabulists: for instance, Franciscus Rueus'34 doubt whether the loadstone were not an imposture of evil spirits: or that, placed underneath the head of an unconscious woman while asleep, it drives her away from the bed if an adulteress: or that the loadstone is of use to thieves by its fume and sheen, being a stone born, as it were, to aid theft: or that it opens bars and locks, as Serapio35 crazily writes: or that iron held up by a loadstone, when placed in the scales, added nothing to the weight of the loadstone, as though the gravity of the iron were absorbed by the force of the stone: or that, as Serapio and the Moors relate, in India there exist certain rocks of the sea abounding in loadstone, which draw out all the nails of the ships which are driven toward them, and so stop their sailing; which fable Olaus Magnus36 does not omit, saying that there are mountains in the north of such great powers of attraction, that ships are built with wooden pegs, lest the iron nails should be drawn from the timber as they passed by amongst the magnetick crags. Nor this: that a white loadstone may be procured as a love potion: or as Hali Abbas37 thoughtlessly reports, that if held in the hand it will cure gout and spasms: Or that it makes one acceptable and in favour with princes, or eloquent, as Pictorio38 has sung; Or as Albertus Magnus39 teaches, that there are two kinds of loadstones, one which points to the North, the other to the South: Or that iron is directed toward the Northern stars by an influence imparted by the polar stars, even as plants follow the sun, as Heliotrope does: Or that there is a magnet-stone situated under the tail of the Greater Bear, as Lucas Gauricus the Astrologer stated: He would even assign the loadstone, like the Sardonyx and onyx, to the planet Saturn, yet at the same time he assigns it with the adamant, Jasper, and Ruby, to Mars; so that it is ruled by two planets. The loadstone moreover is said by him to pertain to the sign Virgo; and he covers many such shameful pieces of folly with a veil of mathematical erudition. Such as that an image of a bear is engraved on a loadstone when the Moon faces towards the north, so that when hung by an iron wire it may conciliate the influence of the celestial Bear, as Gaudentius Merula40 relates: Or that the loadstone drew iron and directed it to the north, because it is superior in rank to iron, at the Bear, as Ficinus writes, and Merula repeats: Or that by day it has a certain power of attracting iron, but by night the power is feeble, or rather null: Or that when weak and dulled the virtue is renewed by goats' blood, as Ruellius41 writes: Or that Goats' blood sets a loadstone free from the venom of a diamond, so that the lost power is revived when bathed in goats' blood by reason of the discord between that blood and the diamond: Or that it removed sorcery from women, and put to flight demons, as Arnaldus de Villanova dreams: Or that it has the power to reconcile husbands to their wives, or to recall brides to their husbands, as Marbodeus Gallus42, chorus-leader of vanities, teaches: Or that in a loadstone pickled in the salt of a sucking fish43 there is power to pick up gold which has fallen into the deepest wells, according to the narratives of Cælius Calcagninus. With such idle tales and trumpery do plebeian philosophers delight themselves and satiate readers greedy for hidden things, and unlearned devourers of absurdities: But after the magnetick nature shall have been disclosed by the discourse that is to follow, and perfected by our labours and experiments, then will the hidden and abstruse causes of so great an effect stand out, sure, proven, displayed and demonstrated; and at the same time all darkness will disappear, and all error will be torn up by the roots and will lie unheeded; and the foundations of a grand magnetick philosophy which have been laid will appear anew, so that high intellects may be no further mocked by idle opinions. Some learned men there are who in the course of long voyages have observed the differences of magnetick variation: the most scholarly Thomas Hariot44, Robert Hues, Edward Wright, Abraham Kendall, all Englishmen; Others there are who have invented and produced magnetical instruments, and ready methods of observation, indispensable for sailors and to those travelling afar: as William Borough45 in his little book on the Variation of the Compass or Magneticall Needle, William Barlowe46 in his Supply, Robert Norman in his Newe Attractive. And this is that Robert Norman47 (a skilful seaman and ingenious artificer) who first discovered the declination of the magnetick needle. Many others I omit wittingly; modern Frenchmen, Germans, and Spaniards, who in books written for the most part in their native tongues either misuse the placets of others, and send them forth furbished with new titles and phrases as tricky traders do old wares with meretricious ornaments; or offer something not worthy of mention even: and these lay hands on some work filched from other authors and solicit some one as their patron, or go hunting after renown for themselves among the inexperienced and the young; who in all branches of learning are seen to hand on errors and occasionally add something false of their own.

2 Page 1, line 28. Page 1, line 28. Plato in Ione.— The passage in the Io of Plato is in chap. v. Socrates addressing the poet Io tells him that his facility in reciting Homer is not really an art: θεία δὲ δύναμις, ἥ σε κινεῖ ὥσπερ ἐν τῇ λίθῳ, ἥν Εὐριπίδης μὲν Μαγνῆτιν ὠνόμασεν, οἱ δὲ πολλοὶ Ἡράκλειαν. καὶ γὰρ ἄυτη ἡ λίθος οὐ μόνον αὐτοὺς τοὺς δακτυλίους ἄγει τοὺς σιδηροῦς, ἀλλὰ καὶ δύναμιν ἐντίθησι τοῖς δακτυλίοις, ὤστ ἄυ δύνασθαι ταυτὸυ τοῦτο ποιεῖν, ὅπερ ἡ λίθος, ἄλλους ἄγειν δακτυλίους, ὥστ' ἐνίοθ' ὁρμαθὸς μακρὸς πάνυ σιδηρίων καὶ δακτυλίων ἐξ ἀλλήλων ἤρτηται πᾶσι δὲ τούτοις ἐξ ἐκείνης τῆς λίθου ἡ δύναμις ἀνήρτηται. The idea is that as the loadstone in attracting an iron ring will make it into a magnet, which can in turn act magnetically on another ring, and this on yet another, so the inspiration of the Muse is transferred to the poet, who in turn hands on the inspiration through the reciter to the listener. After further expanding the same idea of the transference of influence, Socrates again mentions the magnet (chap. vii.): Ὄισθ' ὄυν ὅτι οὐτός ἐστιν ὁ θεατὴς τῶν δακτυλίων ὁ ἔσχατος, ὥν ἐγὼ ἔλεγον ὑπὸ τῆς Ἡρακλειώτιδος λίθου ἀπ' ἀλλήλων τὴν δύναμιν λαμβάνειν, ὁ δὲ μέσος σὺ ὁ ῥαψωδὸς καὶ ὑποκριτής, ὁ δὲ πρῶτος αὐτὸς ὁ ποιητής; ὁ δὲ θεὸς διὰ πάντων τούτων ἕλκει τὴν ψυχὴν ὅποι ἂν βούληται τῶν ἀνθρώπων, κ.τ.λ. (Edition Didot of 1856, vol. i., p. 391; or Stephanus, p. 533 D).

There is another reference in Plato to the magnet, namely, in the Timæus (p. 240, vol. ii., Edit. citat.). See the Note to p. 61.

The reference by Euripides to the magnet occurs in the lost play of Œneus, in a fragment preserved by Suidas. See Fragmenta Euripidis (Ed. Didot, 1846, p. 757, or Nauck's edition, No. 567).

ὡς Εὐριπίδης ἐν Οἰνεῖ· τὰς βροτῶν γνώμας σκοπῶν, ὥστε Μαγνῆτις λίθος τὴν δόξαν ἕλκει καὶ μεθίστησιν πάλιν.

3 Page 1, line 28. Page 1, line 29. The brief passage from Aristotle's De Anima referring to Thales is quoted by Gilbert himself at the bottom of p. 11.

4 Page 2, line 1. Page 1, line 29. The edition of 1628 inserts commas between Theophrastus and Lesbius, and between Julius and Solinus, as though these were four persons instead of two.

5 Page 2, line 8. Page 2, line 5. si allio magnes illitus fuerit, aut si adamas fuerit. An excellent version of this myth is to be found in Julius Solinus, Polyhistor, De Memorabilibus, chap. lxiv., of which the English version of 1587, by A. Golding, runs thus: "The Diamonde will not suffer the Lodestone to drawe yron unto him: or if ye Lodestone haue alreadie drawne a peece of yron to it, the Diamond snatcheth and pulleth away as hys bootye whatsoever the Lodestone hath taken hold of." Saint Augustine repeats the diamond myth in his De Civitate Dei, lib. xxi. Baptista Porta says (p. 211 of the English version of 1658): "It is a common Opinion amongst Sea-men, That Onyons and Garlick are at odds with the Loadstone: and Steers-men, and such as tend the Mariners Card are forbid to eat Onyons or Garlick, lest they make the Index of the Poles drunk. But when I tried all these things, found them to be false: for not onely breathing and belching upon the Loadstone after eating of Garlick, did not stop its vertues: but when it was all anoynted over with the juice of Garlick, it did perform its office as well as if it had never been touched with it: and I could observe almost not the least difference, lest I should make void the endeavours of the Ancients. And again, When I enquired of Marines, whether it were so, that they were forbid to eat Onyons and Garlick for that reason; they said, they were old Wives fables, and things ridiculous; and that Sea-men would sooner lose their lives, then abstain from eating Onyons and Garlick."

The fables respecting the antipathy of garlick and of the diamond to the operation of the magnet, although already discredited by Ruellius and by Porta, died hard. In spite of the exposure and denunciations of Gilbert — compare p. 32— these tales were oft repeated during the succeeding century. In the appendix to Sir Hugh Plat's Jewel House of Art and Nature, in the edition of 1653, by D. B. Gent, it is stated there (p. 218): "The Loadstone which . . . hath an admirable vertue not onely to draw Iron to it self, but also to make any Iron upon which it is rubbed to draw iron also, it is written notwithstanding, that being rubbed with the juyce of Garlick, it loseth that vertue, and cannot then draw iron, as likewise if a Diamond be layed close unto it."

Pliny wrote of the alleged antipathy between diamond and goat's blood. The passage as quoted from the English version of Pliny's Natural Historie of the World, translated by Philemon Holland (London, 1601, p. 610, chap, iv.), runs: "But I would gladly know whose invention this might be to soake the Diamond in Goats bloud, whose head devised it first, or rather by what chance was it found out and knowne? What conjecture should lead a man to make an experiment of such a singular and admirable secret, especially in a goat, the filthiest beast . . . in the whole world? Certes I must ascribe both this invention and all such like to the might and beneficence together of the divine powers: neither are we to argue and reason how and why Nature hath done this or that? Sufficient is it that her will was so, and thus she would have it."

6 Page 2, line 22. Page 2, line 22. Machometis sacellum. Gilbert credits Matthiolus (the well-known herbalist and commentator on Dioscorides) with producing the fable as to Mahomet's coffin being suspended in the air by a magnet. Sir Richard Burton, in his famous pilgrimage to El Medïnah in 1855, effectually disposed of this myth. The reputed sarcophagus rests simply on bricks on the floor. But it had long been known that aerial suspension, even of the lightest iron object, in the air, without contact above or below, was impossible by any magnetic agency.

In Barlowe's Magneticall Aduertisements (London, 1616, p. 45) is the following: "As for the Turkes Mahomet, hanging in the ayer with his yron chest it is a most grosse untruth, and utterly impossible it is for any thing to hange in the ayer by any magneticall power, but that either it must touch the stone it selfe, or else some intermediate body, that hindreth it from comming to the stone (like as before I haue shewed) or else some stay below to keepe it from ascending, as some small wier that may scantly bee seene or perceived."

7 Page 2, line 26. Page 2, line 26. Arsinoes templum.— The account in Pliny of the magnetic suspension of the statue of Arsinoe in the temple built by Chinocrates is given as follows in the English version (London, 1601) of Philemon Holland (p. 515): "And here I cannot chuse but acquaint you with the singular invention of that great architect and master deviser, of Alexandria in Ægypt Dinocrates, who began to make the arched roufe of the temple of Arsinoe all of Magnet or this Loadstone, to the end, that within that temple the statue of the said princesse made of yron, might seeme to hang in the aire by nothing. But prevented he was by death before hee could finish his worke, like as king Ptolomæe also, who ordained that temple to be built in the honour of the said Arsinoe his sister."

There are a number of similar myths in Ausonius, Claudian, and Cassiodorus, and in the writings of later ecclesiastical historians, such as Rusinus and Prosper Aquitanus. The very meagre accounts they have left, and the scattered references to the reputed magical powers of the loadstone, suggest that there existed amongst the primitive religions of mankind a magnet-worship, of which these records are traces.

8 Page 2, line 37. Page 2, line 41. Brasevolus [or Brasavola]. — The list of authorities here cited consists mostly of well-known mediæval writers on materia medica or on minerals: the last on the list, Hannibal Rosetius Calaber, has not been identified.

The following are the references in the order named by Gilbert:

Antonio Musa Brasavola. Examen omnium simplicium medicamentorum, Section 447 (Lugdun., 1537).

Joannes Baptista Montanus. Metaphrasis summaria eorum quæ ad medicamentorum doctrinà attinet (Augustæ Rheticæ, 1551).

Amatus Lusitanus. Amati Lusitani in Dioscoridis Anazarbei de materia medica libros quinque (Venet., 1557, p. 507).

Oribasius. Oribasii Sardiani ad Eunapium libri 4 quibus . . . facultates simplicium . . . continentur (Venet., 1558).

Aetius Amidenus. Aetii Amideni Librorum medicinalium . . . libri octo nunc primum in lucem editi (Greek text, Aldine edition, Venet., 1534). A Latin edition appeared in Basel, 1535. See also his tetrabiblos ex veteribus medicinæ (Basil., 1542).

Avicenna (Ibn Sinâ). Canona Medicinæ (Venice, 1486), liber ii., cap. 474.

Serapio Mauritanus (Yuhanná Ibn Sarapion). In hoc volumine continentur . . . Ioan. Sarapionis Arabis de Simplicibus Medicinis opus præclarum et ingens . . . (edited by Brunfels, Argentorati, 1531, p. 260).

Hali Abbas (’Alí Ibn Al ’Abbās). Liber totius medicinæ necessaria cōtinens . . . quem Haly filius Abbas edidit . . . et a Stephano ex arabica lingua reductus (Lugd., 1523, p. 176 verso).

Santes de Ardoniis (or Ardoynis). Incipit liber de venenis quem magister santes de ardoynis . . . edere cepit venetiis die octauo nouēbris, 1424 (Venet., 1492).

Petrus Apponensis (or Petrus de Abano). The loadstone is referred to in two works by this author.

(1) Conciliator differentiarum philosophorum: et precipue medicorum clarissimi viri Petri de Abano Patauini feliciter incipit (Venet., 1496, p. 72, verso, Quæstio LI.).

(2) Tractatus de Venenis (Roma, 1490, cap. xi.).

Marcellus (called Marcellus Empiricus). De Medicamentis, in the volume Medici antiqui omnes (Venet., 1547, p. 89).

Arnaldus (Arnaldus de Villa Nova). Incipit Tractatus de virtutibus herbarum (Venet., 1499). See also Arnaldi Villanovani Opera omnia (Basil., 1585).

Marbodeus Gallus. Marbodei Galli poetae vetustissimi de lapidibus pretiosis Enchiridion (Friburgi, 1530 [1531], p. 41).

Albertus Magnus. De Mineralibus et rebus metallicis (Venet., 1542, lib. ii., de lapidibus preciosis, p. 192). There is a reference to the loadstone also in a work attributed falsely to Albertus, but now ascribed to Henricus de Saxonia, De virtutibus herbarum, de virtutibus lapidum, etc. (Rouen, 1500, and subsequent editions). An English version, The Secrets of Albertus Magnus of the vertues of hearbs stones and certaine beasts was publisht in London in 1617.

Matthæus Silvaticus. Pandectæ Medicinæ (Lugduni, 1541, cap. 446).

Hermolaus Barbarus. His work, Hermolai Barbari Patritii Veneti et Aqvileiensis patriarchæ Corollarii Libri quinque . . . Venet., 1516, is an early herbal. On p. 103 are to be found descriptions of lapis gagatis and lapis magnes. The latter is mostly taken from Pliny, and mentions the alleged theamedes, and the myth of the floating statue.

Camillus Leonardus. Speculum Lapidum (Venet., 1502, fol. xxxviii.). An English translation, The Mirror of Stones, appeared in London in 1750.

Cornelius Agrippa. Henrici Cor. Agrippæ ab Nettesheym . . . De Occulta Philosophia Libri Tres (Antv., 1531). The English version Of the Vanitie and uncertaintie of Artes was publisht in London, 1569, and again later.

Fallopius (Gabriellus). G. F. de simplicibus medicamentis purgantibus tractatus (Venet., 1566). See also his Tractatus de compositione medicamentorum (Venet., 1570).

Johannes Langius. Epistolarum medicinalium volumen tripartitum (Paris, 1589, p. 792).

Cardinalis Cusanus (Nicolas Khrypffs, Cardinal de Cusa). Nicolai Cusani de staticis experimentis dialogus (Argentorati, 1550). The English edition, entitled The Idiot in four books, is dated London, 1650.

9 Page 3, line 1. Page 2, line 42. Marcellus. —"Marcellus Empiricus, médecin de Théodose-le-Grand, dit que l'aimant, appelé antiphyson, attire et repousse le fer." (Klaproth, Sur l'invention de la boussole, 1834, p. 12.) The passage from Marcellus runs: "Magnetes lapis, qui antiphyson dicitur, qui ferrum trahit et abjicit, et magnetes lapis qui sanguinem emittit et ferrum ad se trahit, collo alligati aut circa caput dolori capitis medentur." (Marcellus, de Medicamentis: in the volume Medici antiqui omnes, qui latinis literis morborum genera persecuti sunt. Venet., 1547, p. 89.)

10 Page 3, line 11. Page 3, line 9. Thomas Erastus. — The work in question is Dispvtationvm de Medicina nova Philippi Paracelsi, Pars Prima: in qua quæ de remediis svperstitiosis & Magicis curationibus ille prodidit, præcipuè examinantur à Thoma Erasto in Schola Heydebergensi, professore. (Basiliæ, 1572. Parts 2 and 3 appeared the same year, and Part 4 in 1573.)

Gilbert had no more love for Paracelsus than for Albertus Magnus or others of the magic-mongers. Indeed the few passages in Paracelsus on the magnet are sorry stuff. They will mostly be found in the seventh volume of his collected works (Opera omnia, Frankfurt, 1603). A sample may be taken from the English work publisht in London, 1650, with the title: Of the Nature of Things, Nine Books; written by Philipp Theophrastus of Hohenheim, called Paracelsvs.

"For any Loadstone that Mercury hath but touched, or which hath been smeered with Mercuriall oyle, or only put into Mercury will never draw Iron more" (p. 23).

"The life of the Loadstone is the spirit of Iron; which may bee extracted, and taken away with spirit of Wine" (p. 32).

11 Page 3, line 13. Page 3, line 11. Encelius (or Entzelt, Christoph) wrote a work publisht in 1551 at Frankfurt, with the title De re metallica, hoc est, de origine, varietate, et natura corporum metallicorum, lapidum, gemmarum, atque aliarum quæ ex fodinis eruuntur, rerum, ad medicine usum deservientium, libri iii. This is written in a singular medley of Latin and German. Gilbert undoubtedly took from it many of his ideas about the properties of metals. See the note to p. 27 on plumbum album.

12 Page 3, line 20. Page 3, line 21. Thomas Aquinas.— The reference is to his commentaries upon the Physica of Aristotle. The passage will be found on p. 96 bis of the Giunta edition (Venet., 1539). The essential part is quoted by Gilbert himself on p. 64.

13 Page 3, line 39. Page 3, line 45. pyxidem.— The word pyxis, which occurs here, and in the next sentence as pyxidem nauticam, is translated compass. Eleven lines lower occurs the term nautica pyxidula. This latter word, literally the "little compass," certainly refers to the portable compass used at sea. Compare several passages in Book IV. where a contrasting use is made of these terms; for example, on pp. 177 and 202. Calcagninus, De re nautica, uses the term pyxidecula for an instrument which he describes as "vitro intecta." On p. 152, line 9, Gilbert uses the non-classical noun compassus, "boreale lilium compassi (quod Boream respicit)," and again on p. 178, line 3.

14 Page 4, line 2. Page 4, line 2. Melphitani.— The inhabitants of Amalfi in the kingdom of Naples. The claim of the discovery or invention of the mariners' compass in the year 1302 by one Joannes Goia, or Gioia, also named as Flavio Goia, has been much disputed. In Guthrie's New System of Modern Geography (London, 1792, p. 1036), in the Chronology, is set down for the year 1302:

"The mariner's compass invented, or improved by Givia, of Naples. The flower de luce, the arms of the Duke of Anjou, then King of Naples, was placed by him at the point of the needle, in compliment to that prince."

In 1808 an elaborate treatise was printed at Naples, by Flaminius Venanson with the title, De l'invention de la Boussole Nautique. Venanson, who cites many authorities, endeavours to prove that if Gioia did not discover magnetic polarity he at least invented the compass, that is to say, he pivotted the magnetic needle and placed it in a box, with a card affixed above it divided into sixteen parts bearing the names of the sixteen principal winds. He alleges in proof that the compass-card is emblazoned in the armorial bearings of the city of Amalfi. This view was combatted in the famous letter of Klaproth to Humboldt publisht in Paris in 1834. He shows that the use of the magnetized needle was known in Europe toward the end of the twelfth century; that the Chinese knew of it and used it for finding the way on land still earlier; that there is no compass-card in the arms of the city of Amalfi; but he concedes that Gioia may have improved the compass in 1302 by adding the wind-rose card. The most recent contributions to the question are a pamphlet by Signorelli, Sull' invenzione della Bussola nautica, ragionamento di Pietro Napoli Signorelli, segretario perpetuo della Società Pontaniana; letto nella seduta del 30 settembre 1860; Matteo Camera's Memorie Storico-diplomatiche dell' antica città e ducato di Amalfi (Salerno, 1876); and Admiral Luigi Fincati's work Il Magnete, la Calamita, e la Bussola (Roma, 1878). An older mention of Gioia is to be found in Blundevile's Exercises (3rd edition, 1606, pp. 257-258). See also Crescentio della Nautica Mediterranea, (Roma, 1607, p. 253), and Azuni, Dissertazione sull' origine della bussola nautica (Venezia, 1797).

There appears to be a slip in Gilbert's reference to Andrea Doria, as he has confounded the town of Amalfi in Principato Citra with Melfi in Basilicata.

One of the sources relied upon by historians for ascribing this origin of the compass is the Compendia dell' Istoria del Regno di Napoli, of Collenuccio (Venet., MDXCI.), p. 5.

"Nè in questo tacerò Amalfi, picciola terra, & capo della costa di Picentia, alia quale tutti quelli, che'l mar caualcano, vfficiosamente eterno gratie debono referire, essendo prima in quella terra trovato l'vso, & l'artificio della calamita, & del bussolo, col quale i nauiganti, la stella Tramontana infallibilmente mirando, direzzano il lor corso, si come è publica fama, & gli Amalfitani si gloriano, nè senza ragione dalli piu si crede, essendo cosa certa, che gli antichi tale instromento non hebbero; nè essendo mai in tutto falso quello, che in molto tempo è da molti si diuolga."

Another account is to be found in the Historiarum sui temporis, etc., of Paulus Jovius (Florent., 1552), tom. ii., cap. 25, p. 42.

"Quum essem apud Philippum superuenit Ioachinus Leuantius Ligur a Lotrechio missus, qui deposceret captiuos; sed ille negauit se daturum, quando eos ad ipsum Andream Auriam ammirantem deducendos esse iudicaret. Vgonis uerò cadauer, ut illudentium Barbarorum contumeliis eriperetur, ad Amalphim urbem delatum est, in ædeque Andreæ apostoli, tumultuariis exequiis tumulatum. In hac urbe citriorum & medicorum odoratis nemoribus æquè peramœna & celebri, Magnetis usum nauigantibus hodie familiarem & necessarium, adinuentum suisse incolæ asserunt."

Flavius Blondus, whom Gilbert cites, gives the following reference, in which Gioia's name is not mentioned, in the section upon Campania Felix of his Italy (Blondi Flavii Forlinensis . . . Italia Illustrata, Basiliæ, 1531, p. 420).

"Sed fama est qua Amalphitanos audiuimus gloriari, magnetis usum, cuius adminiculo nauigantes ad arcton diriguntur, Amalphi suisse inuentum, quicquid uero habeat in ea re ueritas, certû est id noctu nauigandi auxilium priscis omnino suisse incognitum."

There is a further reference to the alleged Amalphian in Caelius Calcagninus De re nautica commentatio. (See Thesaurus Græcarum Antiquitatum, 1697, vol. xi., p. 761.) On the other hand Baptista Porta, who wrote in Naples in 1558 (Magia Naturalis) distinctly sets aside the claim as baseless.

William Barlowe, in The Navigators Supply (1597, p. A3), says: "Who was the first inuentor of this Instrument miraculous, and endued, as it were, with life, can hardly be found. The lame tale of one Flauius at Amelphis, in the kingdome of Naples, for to haue deuised it, is of very slender probabilitie. Pandulph Collenutius writing the Neapolitane historie telleth vs, that they of Amelphis say, it is a common opinion there, that it was first found out among them. But Polidore Virgil, who searched most diligently for the Inuentors of things, could neuer heare of this opinion (yet himselfe being an Italian) and as he confesseth in the later ende of his third booke de inventoribus rerum, could neuer vnderstand anything concerning the first inuention of this instrument."

According to Park Benjamin (Intellectual Rise in Electricity, p. 146) the use of the pivotted compass arose and spread not from Amalfi at the hands of Italians in the fourteenth century, but from Wisbuy, at the hands of the Finns, in the middle of the twelfth century.

Hakewill (An Apologie or Declaration of the Power and Providence of God, London, 1673, pp. 284-285) says:

"But Blondus, who is therein followed by Pancirollus, both Italians, will not haue Italy loose the praise thereof, telling vs that about 300 yeares agoe it was found out at Malphis or Melphis, a Citty in the Kingdome of Naples in the Province of Campania, now called Terra di Lovorador. But for the Author of it, the one names him not, and the other assures vs, he is not knowne: yet Salmuth out of Ciezus & Gomara confidently christens him with the name of Flavius, and so doth Du Bartas in those excellent verses of his touching this subject.

"'W' are not to Ceres so much bound for bread,

Neither to Bacchus for his clusters red,

As Signior Flavio to thy witty tryall,

For first inventing of the Sea-mans dyall,

Th' vse of the needle turning in the same,

Divine device, O admirable frame!'

"It may well be then that Flavius the Melvitan was the first inventor of guiding the ship by the turning of the needle to the North: but some German afterwards added to the Compasse the 32 points of the winde in his owne language, whence other Nations haue since borrowed it."

15 Page 4, line 14. Page 4, line 14. Paulum Venetum. — The reference is to Marco Polo. He returned in 1295 from his famous voyage to Cathay. But the oft-repeated tale that he first introduced the knowledge of the compass into Europe on his return is disposed of by several well-established facts. Klaproth (op. citat., p. 57) adduces a mention of its use in 1240 in the Eastern Mediterranean, recorded in a work written in 1242 by Bailak of Kibdjak. And the passages in the Iceland Chronicle, and in Alexander of Neckham are still earlier.

16 Page 4, line 17. Page 4, line 17. Goropius. See Hispanica Ioannis Goropii Becani (Plantin edition, Antv., 1580), p. 29. This is a discussion of the etymologies of the names of the points of the compass: but is quite unauthoritative.

17 Page 4, line 23. Page 4, line 26. Paruaim. — Respecting this reference, Sir Philip Magnus has kindly furnisht the following note. A clue to the meaning of Parvaim, which should be written in English letters with a v, not a u, will be found in 2 Chronicles, iii. 6. In the verse quoted the author speaks of gold as the gold of Parvaim, וְהַזָּהָב זְהַב פַּרְוָיִם‎, and פּרוים‎ Parvaim is taken as a gold-producing region. It is regarded by some as the same as Ophir. The word is supposed to be cognate with a Sanskrit word pûrva signifying "prior, anterior, oriental." There is nothing in the root indicating gold. A form similar to Parvaim, and also a proper name, is Sepharvaim, found in 2 Kings, xix. 13, and in Isaiah, xxxvii. 13, and supposed to be the name of a city in Assyria.

18 Page 4, line 35. Page 4, line 41. Cabot's observation of the variation of the compass is narrated in the Geografia of Livio Sanuto (Vinegia, 1588, lib. i., fol. 2). See also Fournier's Hydrographie, lib. xi., cap. 10.

19 Page 4, line 36. Page 4, line 42. Gonzalus Oviedus. — The reference is to Gonzalo Fernandez de Oviedo y Valdès. Summario de la Historia general y natural de las Indias occidentales, 1525, p. 48, where the author speaks of the crossing of "la linea del Diametro, donde las Agujas hacen la diferencia del Nordestear, ò Noroestear, que es el parage de las Islas de los Açores."

20 Page 5, line 8. Page 5, line 11. Petri cujusdam Peregrini. — This opusculum is the famous letter of Peter Peregrinus written in 1269, of which some twenty manuscript copies exist in various libraries in Oxford, Rome, Paris, etc., and of which the oldest printed edition is that of 1558 (Augsburg). See also Libri, Histoire des Sciences Mathématiques (1838); Bertelli in Boncompagni's Bull. d. Bibliogr. T. I. and T. IV. (1868 and 1871), and Hellmann's Rara Magnetica (1898). A summary of the contents of Peregrinus's book will be found in Park Benjamin's Intellectual Rise in Electricity (1895), pp. 164-185.

21 Page 5, line 12. Page 5, line 15. Johannes Taisner Hannonius.— Taisnier, or Taysnier, of Hainault, was a plagiarist who took most of the treatise of Peregrinus and publisht it in his Opusculum . . . de Natura Magnetis (Coloniæ, 1562), of which an English translation by Richard Eden was printed by R. Jugge in 1579.

22 Page 5, line 18. Page 5, line 23. Collegium Conimbricense. — This is a reference to the commentaries on Aristotle by the Jesuits of Coimbra. The work is Colegio de Coimbra da Companhia de Jesu, Cursus Conimbricensis in Octo libros Physicorum (Coloniæ, sumptibus Lazari Ratzneri, 1599). Other editions: Lugd. 1594; and Colon., 1596. The later edition of 1609, in the British Museum, has the title Commentariorum Collegii Conimbricensis in octo libros physicorum.

23 Page 5, line 25. Page 5, line 31. Martinus Cortesius. — His Arte de Navegar (Sevilla, 1556) went through various editions in Spanish, Italian, and English. Eden's translation was publisht 1561, and again in 1609.

24 Page 5, line 26. Page 5, line 33. Bessardus. — Toussaincte de Bessard wrote a treatise, Dialogue de la Longitude (Rouen, 1574), which gives some useful notes of nautical practice, and of the French construction of the compass. Speaking of the needle he says: "Elle ne tire pas au pole du monde: ains regarde, au Pole du Zodiaque, comme il sera discoursu, cy apres" (p. 34). On p. 50 he speaks of "l'aiguille Aymantine." On p. 108 he refers to Mercator's Carte Générale, and denies the existence of the alleged loadstone rock. On p. 15 he gives the most naïve etymologies for the terms used: thus he assigns as the derivation of Sud the Latin sudor, because the south is hot, and as that of Ouest that it comes from Ou and Est. "Come, qui diroit, Ou est-il? à scauoir le Soleil, qui estoit nagueres sur la terre."

25 Page 5, line 28. Page 5, line 35. Jacobus Severtius. — Jacques Severt, whose work, De Orbis Catoptrici sev mapparvm mvndi principiis descriptione ac usu libri tres (Paris, 1598), would have probably lapsed into obscurity, but being just newly publisht was mentioned by Gilbert for its follies.

26 Page 5, line 30. Page 5, line 38. Robertus Norman. — Author of the rare volume The Newe Attractiue, publisht in London, 1581, and several times reprinted. This work contains an account of Norman's discovery 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 à vero Septentrione, quandoque ad dextram, 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 malitiosè nauticum gnomonem, aut compassum, & præcipuè 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 dicũ uires amittit: propterea quòd ilia insula plena est magnetum."

This myth of the magnetic mountains, probably originating with Nicander, appears, possibly from an independent source, in the East, in China, and in the tales of the Arabian Nights.

Ptolemy gives the following account in his Geographia (lib. vii., cap. 2):

Φέρονται δὲ καὶ ἄλλαι συνεχεῖς δέκα νῆσοι καλούμεναι Μανίολαι ἐν ἄις φάσι τὰ σιδήρους ἔχοντα ἥλους πλοῖα κατέχεσθαι, μήποτε τῆς Ἡρικλείας λίθου περὶ αὐτὰς γενομένης, καὶ διὰ τοῦτο ἐπιούροις ναυπηγεῖσθαι. Some editions omit the name of the Manioles from the passage.

No two authorities agree as to the place of these alleged magnetic mountains. Some place them in the Red Sea. Fracastorio, De Sympathia et Antipathia, cap. 7 (Opera omnia, Giunta edition, 1574, p. 63), gives the following reason for the variation of the compass:

"Nos igitur diligentius rem considerãtes dicimus causam, q̃ perpendiculum illud ad polum vertatur, esse montes ferri, & magnetis, qui sub polo sunt, vt negociatores affirmant, quorum species per incredibilem distantiam vsque ad maria nostra propagata ad perpendiculum vsq;, vbi est magnes, consuetam attractionem facit: propter distantiam autem quum debilis sit, non moueret quidem magnetem, nisi esset in perpendiculo: quare & si non trahit vsq; ac. principium, vnde effluxit, at mouet tamẽ, & propinquiorem facit, quo potest. Quod si naues sorte vllæ propinquiores sint illis montibus, ferrum omne earũ cuellitur, propter quod nauigijs incolæ vtuntur clauis ligneis astrictis."

In the last chapter of his De Sympathia, Fracastorio returns to the subject in consequence of some doubts expressed by Giambattista Rhamnusio, seeing that the loadstones in the Island of Elba do not sensibly deflect the magnet. Fracastorio replies thus (p. 76, op. citat.):

"Primum igitur vtrum sub Polo sint. Magnetis mõtes, nec ne, sub ambiguo relinquamus, scimus enim esse, qui scribãt planas magis esse eas regiones, de quo Paulus Iouius Ep̃us Nucerinus Luculẽtus historiarũ nostri tẽporis scriptor, circa eã Sarmatiæ partem, quæ Moscouia nũc dicitur, diligentẽ inquisitionem ab incolis fecit, qui ne eos etiã inueniri montes retulere, qui Rhyphei ab antiquis dicti sunt: meminimus tamẽ nos quasdam chartas vidisse earum, quas mundi mappas appellãt, in quibus sub polo montes notati erant (qui Magnetis montes inscripti fuerant). Siue igitur sint, siue non sint ij montes, nihil ad nos in præsentiarum attinet, quando per montes polo subiectos cathenam illam montium intelligimus, qui ad septentrionem spectant tanti, & tam vasti, ac Ferri & Magnetis feraces: qui, & si magis distant à nostro mari, q̃ Iluæ insulæ montes, potentiores tamen sunt ad mouendum perpendiculum propter abundantiam & copiã Ferri, & Magnetis. Fortasse autem, & qui in Ilua est Magnes, non multæ actionis est in ea minera: multi enim dũ in minera sunt, minus valent, q̃ extracti, q̃ spirituales species sua habeant impedimenta: signum autem parum valere in sua minera Iluæ insulæ Magnetem, q̃ tam propinquus quum sit nauigijs illac prætereuntibus, perpendiculum tamen non ad se cõuertit."

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, 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):

"Now betwixt the 72. and 86. degrees of North latitude he setteth downe two long Ilands extending from the West towardes the East somewhat beyond the first Meridian, and from the saide Meridian more Eastward he setteth downe other two long Ilandes . . . and hee saith further that right under the North pole there is a certaine blacke and most high rocke which hath in circuite thirtie and three leagues, which is nintie and nine miles, and that the long Iland next to the Pole on the West is the best and most healthfull of all the North parts. Next to the foresaide Ilandes more Southward hee setteth downe the Ilandes of Crocklande and Groynelande, making them to haue a farre longer and more slender shape then all other mappes doe. . . . Moreouer at the East end of the last Ilande somewhat to the Southwarde, he placeth the Pole of the Lodestone which is called in Latine Magnes, euen as Mercator doth in his Mappe who supposing the first Meridian to passe through Saint Marie or Saint Michael, which are two of the outermost Ilandes of the Azores Eastwarde, placeth the Pole of the stone in the seuentie fiue degree of Latitude, but supposing the first Meridian to passe through the Ile Coruo, which is the furthest Ile of the Azores Westwarde, he placeth the Pole of the Lodestone in the seuentie seuen degree of Latitude."

Further, in the chapter on The Arte of Nauigation in the same work (p. 332, ed. citat.), Blundevile says:

"But whereas Mercator affirmeth that there should bee a mine or great rocke of Adamant, wherunto all other lesser rockes or Needles touched with the Lodestone doe incline as to their chiefe fountaine, that opinion seemeth to mee verie straunge, for truely I rather beleeue with Robert Norman that the properties of the Stone, as well in drawing steele, as in shewing the North Pole, are secret vertues given of GOD to that stone for mans necessarie vse and behoofe, of which secrete vertues no man is able to shewe the true cause."

The following is one of the inscriptions in the compartments of the great Chart of Mercator entitled Ad Usum Navigantium, published in 1569:

"Testatur Franciscus Diepanus peritissimus nauarchus volubiles libellas, magnetis virtute infectas recta mundi polum respicere in insulis C. Viridis, Solis, Bonauista, et Maio, cui proxime astipulantur qui in Tercera, aut S. Maria (insulæ sunt inter Açores) id fieri dicunt, pauci in earundem occidentalissima Corvi nomine id contingere opinantur. Quia vero locorum longitudinis a communi magnetis et mundi meridiano iustis de causis initium sumere oportet, plurium testimonium sequutus primum meridianum per dictas C. Viridis insulas protraxi, et quum alibi plus minusque a polo deuiante magnete polum aliquum peculiarem esse oporteat quo magnetes ex omni mundi parte despiciant, euum hoc quo assignaui loco existere adhibita declinatione magnetis Ratisbonæ obseruata didici. Supputaui autem eius poli situm etiam respectu insulæ Corui, ut iuxta extremo primi meridiani positus extremi etiam termini, intra quos polum hunc inueniri necesse est, conspicui fierent, donec certius aliquod nauclerorum obseruatio attulerit."

Not all the map-makers were as frank as Paulus Merula, the author of a Cosmographia Generalis, printed by Plantin in 1605, at Leyden. For in the description of his tabula universalis (op. citat. lib. iii., cap. 9) he says that he does not believe in the magnetic islands; but that he has put them into his chart lest unskilful folk should think that he had been so careless as to leave them out!

In the well-known myth of Ogier the Dane, immortalized by William Morris in the Earthly Paradise (London, 1869, vol. i., p. 625), the loadstone rock is an island in the far North. But this story is not one of the Scandinavian sagas, and belongs to the Carlovingian cycle of heroic poems, of which the chief is the Chanson de Roland; and Ogier le Danois is really not a Dane but an Ardennois.

In the Middle-High German epic of Kudrun, the adventures of the fleet of Queen Hilda when attracted by the loadstone mountain at Givers, in the North Sea, are narrated at some length. (See Kudrun, herausgegeben und erklärt von Ernst Martin. Halle, 1872.) One stanza will serve as a sample:

1126. Ze Givers vor dem berge | lac daz Hilden her.

swie guot ir anker wæren, | an daz vinster mer.

magnêten die steine | heten si gezogen.

ir guote segelboume | stuonden alle gebogen.

which may be rendered:

1126. At Givers before the mountain | lay Hilda's ships by.

Though good their anchors were, | upon the murky sea.

Magnets the stones were | had drawn them thither.

Their good sailing masts | stood all bent together.

Recent magnetic research has shown that while there are no magnetic mountains that would account for the declination of the compass in general, yet there are minor local variations that can only be accounted for by the presence of magnetic reefs or rocks. The reader is referred to the account of the magnetic survey of Great Britain in the Philosophical Transactions (1890) by Professors Rücker and Thorpe. The well-known rocky peak the Riffelhorn above Zermatt, in Switzerland, produces distinct perturbations in the direction of the compass within half a mile of its base. Such local perturbations are regularly used in Sweden for tracing out the position of underground lodes of iron ore. See Thalén, Sur la Recherche des Mines de Fer à l'aide de Mesures magnétiques (Soc. Royale des Sciences d'Upsal, 1877); or B. R. Brough, The Use of the Magnetic Needle in exploring for Iron Ore (Scientific American, Suppl. No. 608, p. 9708, Aug. 27, 1887).

Quite recently Dr. Henry Wilde, F.R.S., has endeavoured to elucidate the deviations of the compass as the result of the configurations of land and sea on the globe, by means of a model globe in which the ocean areas are covered with thin sheet iron. This apparatus Dr. Wilde calls a Magnetarium. See Proc. Roy. Soc., June, 1890, Jan., 1891, and June, 1891. An actual magnetic rock exists in Scandinavia, the following account of it being given in the Electrical Review of New York, May 3, 1899:

"The island of Bornholm in the Baltic, which consists of a mass of magnetic iron ore, is much feared by mariners. On being sighted they discontinue steering by compass, and go instead by lighthouses. Between Bornholm and the mainland there is also a dangerous bank of rock under water. It is said that the magnetic influence of this ore bank is so powerful that a balanced magnetic needle suspended freely in a boat over the bank will take a vertical position."

29 Page 5, line 35. Page 5, line 43. Josephus Costa.— This is unquestionably a misprint for Acosta (Joseph de), the Jesuit, whose work Historia natural y moral de las Indias was publisht at Seville in 1590. An Italian edition appeared at Venice in 1596. The English edition, translated by E. Grimestone, The Naturall and Morall Historie of the East and West Indies, was publisht in London in 1604 and 1878. There are in Gilbert's book references to two writers of the name of Costa or Costæus, Joannes Costa of Lodi, who edited Galen and Avicenna (see pp. 3 and 62), and Filippo Costa of Mantua, who wrote on antidotes and medicaments (see p. 141). The passage to which Gilbert refers is in Acosta's Historia (ed. 1590, p. 64).

"Deziame a mi vn piloto muy diestro Portugues q̃ eran quatro puntos en todo el orbe, donde se afixaua el aguja con el Norte, y contaualas por sus nombres, de que no me acuerdo bien. Vno destos es el paraje de la Isla del Cueruo, en las Terceras, o Islas de Açores, como es cosa y a muy sabida. Passando di alli a mas altura, Noruestea, que es dezir, q̃ declina al Poniente . . . que me digã la causa desta efecto? . . . Porque vn poco de hierro de fregarse cõ la piedra Iman . . .

"Mejor es, como dize Gregorio Theologo, que a la Fe se sujete la razon, pues aun en su casa no sabe bien entenderse. . . . "

30 Page 5, line 36. Page 5, line 45. Livius Sanutus.— Livio Sanuto publisht at Venice in 1588 a folio work, Geografia distinta in xii Libri; ne' quali, oltre l'esplicatione di nostri luoghi di Tolomeo, della Bussola e dell' Aguglia, si dichiarono le provincie . . . dell' Africa. In this work all Liber i. (pages 1-13) deals with observations of the compass, mentioning Sebastian Cabot, and other navigators. He gives a map of Africa, showing the central lakes out of which flow the Zaires fluvius and the Zanberes fluvius.

31 Page 6, line 2. Page 6, line 5. Fortunius Affaitatus.— The work of Affaytatus, Physicæ ac astronomiæ considerationes, was publisht in Venice in 1549.

32 Page 6, line 3. Page 6, line 6. Baptista Porta.— The reference is to his celebrated Magia naturalis, the first edition of which came out in 1558 at Naples. An English edition, Natural Magick by John Baptista Porta, a Neapolitaine, was printed in London, 1658. Book seven of this volume treats "Of the wonders of the Load-stone." In the proem to this book Porta says: "I knew at Venice R. M. Paulus, the Venetian, that was busied in the same study: he was Provincial of the Order of servants, but now a most worthy Advocate, from whom I not only confess, that I gained something, but I glory in it, because of all the men I ever saw, I never saw any man more learned, or more ingenious, having obtained the whole body of learning; and is not only the Splendor and Ornament of Venice or Italy, but of the whole world." The reference is to Fra Paolo Sarpi, better known as the historian of the Council of Trent. Sarpi was himself known to Gilbert.

His relations with Gilbert are set forth in the memoir prefixt to the edition of his works, Opere di Fra Paolo Sarpi, Servita . . . in Helmstat, MDCCLXI, p. 83. "Fino a questi giorni continuava il Sarpi a raccorre osservazioni sulla declinazione dell' Ago Calamitato; e poi ch' egli, atteso il variare di tal declinazione, assurdità alcuna non trovava riguardo al pensamento dell' Inglese Guglielmo Gilberto, cioè, che l'interno del nostro Globo fosse gran Calamita. . . . " Here follows a quotation from a letter of Sarpi to Lescasserio:

" . . . Unde cuspidem trahi a tanta mole terrena, quæ supereminet non absurde putavit Gullielmus Gilbertus, et in eo meridiano respicere recta polum, cave putes observatorem errasse. Est Vir accuratissimus, et interfuit omnibus observationibus, quas plures olim fecimus, et aliquas in sui gratiam, et cum arcubus vertici cupreo innitentibus, et cum innatantibus aquæ, et cum brevibus, et cum longis, quibus modis omnibus et Hierapoli usus suit."

Sarpi had correspondence with Gilbert, Bacon, Grotius, and Casaubon. He also wrote on magnetism and other topics in materia di Fisica, but these writings have perisht. He appears to have been the first to recognize that fire destroyed the magnetic properties. (See Fra Paolo Sarpi, the greatest of the Venetians by the Rev. Alexander Robertson, London, 1894; see also the notice of Sarpi in Park Benjamin's Intellectual Rise in Electricity.)

33 Page 6, line 7. Page 6, line 11.: R. M. Paulus Venetus. See preceding note.

34 Page 6, line 21. Page 6, line 28.: Franciscus Rueus. — Francois de la Rue, author of De Gemmis Aliquot . . . (Paris, 1547). Amongst other fables narrated by Rueus is that if a magnet is hung on a balance, when a piece of iron is attracted and adheres to the magnet, it adds nothing to the weight!

35 Page 6, line 25. Page 6, line 33.: Serapio. — This account of the magnetic mountains will be found in an early pharmacology printed in 1531 (Argentorati, G. Ulricher Andlenus), with the title "In hoc volumine continetur insignium medicorum Joan. Serapionis Arabis de Simplicibus Medicinis opus præclarum et ingens, Averrois Arabis de eisdem liber eximius, Rasis filius Zachariæ de eisdem opusculum perutile." It was edited by Otho Brunsels. Achilles P. Gasser, in his Appendix to the Augsburg edition of Peregrinus, gives a reference to Serapio Mauritanus, parte 2, cap. 394, libri de medicinis compositis.

36 Page 6, line 30. Page 6, line 39.: Olaus Magnus. See note to p. 5.

37 Page 6, line 34. Page 6, line 44.: Hali Abas. — A reference is given in Gasser's (1558) edition of Peregrinus to Haliabbas Arabs, lib. 2, practicæ cap. 45, Regalis Dispositionis Medicinæ. The passage to which Gilbert refers is found in the volume Liber totius medicinæ necessaria cōtinens . . . quem Haly filius Abbas . . . edidit . . . et a Stephano ex arabica lingua reductus. (Lugd., 1523, 4to.) Liber Primus. Practice, Cap xlv. de speciebus lapidum, § 466. "Lapis magnetes filis e vtute sadenego: & aiunt qm si teneatr in manu mitigat q sunt in pedibs ipis dolores ac spasmū."

Mr. A. G. Ellis identifies the noun sadenegum as a Latin corruption of the Arabic name of hæmatite, shâdanaj.

38 Page 6, line 36. Page 6, line 46.: Pictorius. — His poem was publisht at Basel, 1567. See also note on Marbodæus, p. 7, line 20, below.

39 Page 6, line 36. Page 7, line 1.: Albertus Magnus. — Albertus, the celebrated Archbishop of Ratisbon, is responsible for propagating sundry of the myths of the magnet; and Gilbert never loses a chance of girding at him. The following examples are taken from the treatise De mineralibus et rebus metallicis (Liber II. de lapidibus preciosis), Venet., 1542.

p. 171. "Et quod mirabile videtur multis his lapis [adamas] quando Magneti supponitur ligat Magnetem et non permittit ipsum ferrum trahere."

p. 193. "Vnctus autẽ lapis alleo non trahit, si superponitur ei Adamas iterum non attrahit, ita quod paruus Adamas magnũ ligat Magnetẽ. Inventus autẽ est nostris tẽporibus Magnes qui ab uno angulo traxit ferrũ et ab alio fugavit, et hunc Aristot. ponit aliud genus esse Magnetis. Narrauit mihi quidam ex nostris sociis experimẽtator quod uidit Federicum Imperatorem habere Magnetem qui non traxit ferrum, sed ferrum uiceuersa traxit lapidem."

The first edition of this work de mineralibus appears to have been publisht in Venice as a folio in 1495.

40 Page 7, line 9. Page 7, line 15. Gaudentius Merula. — This obscure passage is from Liber IIII., cap. xxi., Lapides, of the work Memorabilium Gaudentii Merulæ . . . (Lugd., 1556), where we find:

"Qui magneti vrsæ sculpserit imaginem, quãdo Luna melius illuc aspiciat, & filo ferreo suspẽderit, compos fiet vrsæ cælestis virtutis: verùm cum Saturni radiis vegetetur, satius fuerit eam imaginem non habere: scribunt enim Platonici malos dæmones septentrionales esse" (p. 287).

"Trahit autem magnes ferrum ad se, quod ferro sit ordine superior apud vrsum" (p. 287).

The almost equally obscure passage in the De triplici vita of Marsiglio Ficino (Basil., 1532) runs:

"Videmus in specula nautarum indice poli libratum acum affectum in extremitate Magnete moueri ad Vrsam, illuc uidelicet trahente Magnete: quoniam & in lapide hoc præualet uirtus Vrsæ, & hinc transfertur in ferrum, & ad Vrsam trahit utrunq;. Virtus autem eiusmodi tum ab initio infusa est, tum continue Vrsæ radijs uegetatur, Forsitan ita se habet Succinum ad polum alterum & ad paleas. Sed dic interea, Cur Magnes trahit ubiq; ferrum? non quia simile, alioquin & Magnetem Magnes traheret multo magis, ferrumq; ferrū: non quia superior in ordine corporum, imò superius est lapillo metallum . . . Ego autem quum hæc explorata hactenus habuissem admodum gratulabar, cogitabamq; iuuenis adhuc Magneti pro uiribus inscluperet (sic) coelestis Vrsæ figuram, quando Luna melius illuc aspiciat, & ferro tūc filo collo suspendere. Sperabam equidem ita demum uirtutis me sideris illius compotem fore," &c. (p. 172).

41 Page 7, line 14. Page 7, line 20. Ruellius. — Joannes Ruellius wrote a herbal De Natura Stirpium, Paris, 1536, which contains a very full account of amber, and a notice of the magnet (p. 125) and of the fable about garlic. But on p. 530 of the same work he ridicules Plutarch for recording this very matter.

42 Page 7, line 20. Page 7, line 27. Marbodæus Gallus. — This rare little book is entitled Marbodei Galli Poetæ vetustissimi de lapidibus pretiosis Enchiridion. It was printed at Paris in 1531. The Freiburg edition, also of 1531, has the commentaries of Pictorius. The poem is in Latin hexameters. After a preface of twenty-one lines the virtues of stones are dealt with, the paragraph beginning with a statement that Evax, king of the Arabs, is said to have written to Nero an account of the species, names and colours of stones, their place of origin and their potencies; and that this work formed the basis of the poem. The alleged magical powers of the magnet are recited in Caput I., Adamas. Caput XLIII., Magnes, gives further myths. The commentary of Pictorius gives references to earlier writers, Pliny, Dioscorides, Bartholomæus Anglicus, Solinus, Serapio, and to the book de lapidibus erroneously ascribed to Aristotle.

The following is a specimen of the poem of Marbodeus:

Magnetes lapis est inuentus apud Trogloditas,

Quē lapidā genetrix nihilominus India mittit.

Hic ferruginei cognoscitur esse coloris,

Et ui naturæ uicinum tollere ferrum.

Ededon magus hoc primum ferè dicītur usus,

Conscius in magica nihil esse potentius arte.

Post illum fertur famosa uenefica Circe

Hoc in præstigijs magicis specialiter usa.

This poem was reprinted (1854) in Migne's Patrologia. In 1799 Johann Beckmann issued an annotated variorum edition of Marbodeus (Marbodi Liber Lapidvm sev de Gemmis . . ., Göttingæ, 1799), in which there is a bibliography of the poem, the first edition of which appears to have been publisht in 1511, at Vienna, thirteen other editions being described. Beckmann adds many illustrative notes, and a notice of the Arabian Evax, who is supposed to have written the treatise de lapidibus. Not the least curious part is a French translation alleged to have been written in 1096, of which Chap. XIX. on the Magnet begins thus:

Magnete trovent Trogodite,

En Inde e precieus est ditte.

Fer resemble e si le trait,

Altresi cum laimant fait.

Dendor lama mult durement.

Qi lusoit a enchantement.

Circe lus a dot mult chere,

Cele merveillose forciere, &c.

43 Page 7, line 21. Page 7, line 28. echeneidis.— The echeneis, or sucking-fish, reputed to have magical or magnetic powers, is mentioned by many writers. As an example, see Fracastorio, De Sympathia et Antipathia, lib. i., cap. 8, De Echineide, quomodo firmare nauigia possit (Giunta edition, Venet., 1574, p. 63). For other references to the Echeneis see Gaudentius Merula (op. citat.) p. 209. Also Dr. Walter Charleton, Physiologia Epicuro Gassendo-Charltoniana (Lond., 1654), p. 375. Compare p. 63, line 3.

44 Page 7, line 33. Page 7, line 43. Thomas Hariotus, etc. — The four Englishmen named were learned men who had contributed to navigation by magnetic observations. Harriot's account of his voyage to Virginia is printed in Hakluyt's Voyages. Robert Hues (or Hood) wrote a treatise on Globes, the Latin edition of which appeared in 1593 (dedicated to Sir Walter Raleigh), and the English edition in 1638. It was republisht by the Hakluyt Society, 1889. Edward Wright, the mathematician and writer on navigation, also wrote the preface to Gilbert's own book. Abraham Kendall, or Abram Kendal was "Portulano," or sailing-master of Sir Robert Dudley's ship the Bear, and is mentioned in Dudley's Arcano del Mare. On the return of Dudley's expedition in 1595, he joined Drake's last expedition, which sailed that year, and died on the same day as Drake himself, 28 January, 1596. (See Hakluyt, ed. 1809, iv., p. 73.)

45 Page 7, line 36. Page 8, line 1. Guilielmus Borough.— Borough's book has the title: A Discours of the Variation of the Cumpas, or magneticall Needle. Wherein is Mathematically shewed, the manner of the obseruation, effectes, and application thereof, made by W. B. And is to be annexed to The Newe Attractive of R. N., 1581 (London).

46 Page 7, line 37. Page 8, line 2. Guilielmus Barlo. — Archdeacon William Barlowe (author, in 1616, of the Magneticall Aduertisements) wrote in 1597 a little work called The Navigators Supply. It gives a description of the ordinary compass, and also one of a special form of meridian compass provided with sights for taking the bearings by the sun.

47 Page 7, line 37. Page 8, line 3. Robertus Normannus. See Note to p. 5.

http://ebooks.adelaide.edu.au/g/gilbert/william/on-the-magnet/book1.1.html

Last updated Friday, March 14, 2014 at 22:17