GIOIA, Flavio, a pilot or ship-captain, was born at Pasitano, a village situated near Amain, about the end of the thirteenth century. During a long period this navigator was generally regarded as the inventor of the mariner’s compass; and so precise were the ideas of some writers on the subject, that they fixed the year 1302 or 1303 as the date of the invention. But every one now knows that the claims of Gioia have been disputed; that, according to some, he did not invent, but only improved, the compass; whilst, in the opinion of others, he had nothing whatever to do either with the invention or improvement of an instrument which, in a certain sense, may be said to have changed the face of the world. To render him justice, however, it is necessary to recall the most remarkable opinions which have been expressed on the subject, and, in particular, to indicate the facts by which these opinions are sought to be supported.

Polydore Virgil places the invention of the compass amongst those the authors of which are unknown. Om- [7:10:526]nino in aperto non est, ^[1. Polydor. Virg. De Invent. Rer. lib. HL c. 18. ] says he; and however superficial this writer may be, his testimony is of great weight against Gioia, as he was born in Italy only two hundred years after the celebrated navigator of Amalfi. Several learned men have attributed the invention of the compass to the Phoenicians, to the Tyrians, and to King Solomon respectively. Court de Gébelin is one of those who attribute it to the Phoenicians. Others, misled by an ill-interpreted passage of Plautus, have supposed that the Greeks and Romans were acquainted with the compass. In this number is Abundantius Collina, who, in a memoir entitled De Acus Nautic<e Inventore, ^[2. Bonon. Instit. Comment, tome ii. part 3. ] has promulgated such a notion. But these opinions have been completely refuted by Turnebus, Bochart, and Dutens; by Trom-belli, De Acus Nauticae Inventore ; ^[3. Bonon. Instit. Comment, tome ii. part 3. ] by Grimaldi, Sopra il primo Inventore della Bussola ;^[4. Recueil de l’Acad. de Cortone. tome iii. ] by Montucla in his Histoire des Mathématiques ; and more recently by Azuni, in a Dissertation on the Origin of the Compass, printed twice in Italian, and then in French, Paris, 1807, in 8vo. In fact, the ancients knew not the directive virtue of the magnet. The silence of all the authors of antiquity, who have spoken of the loadstone, particularly of Lucretius, Pliny, Claudian, and Plutarch, forms a negative proof of their ignorance of this quality which seems quite insuperable. Gerbert of Auvergne, born about the commencement of the tenth century, and afterwards pope under the name of Silvester II., being desirous, when he was bishop of Magdeburg, to construct a horizontal solar dial, found the north point by the help of an instrument with which he observed the pole star; in Magdeburg horologium fecit, illud recte constituens, considerata per fistulam quamdam stella Nautarum duce. ^[5. Di th mar. Chronic, apud Leibnitz, Scriptore· Ber. Brunew. tome 1. p. 399. ] Father Costadau, Collina, and others, have thought that, in the instrument here mentioned, they recognized the compass. But Montucla has refuted this erroneous opinion, and shown that the instrument of Gerbert was merely a tube (fistula), which he directed towards the pole star in order to determine the meridian line. Evidence more convincing, however, attests that the navigators of the Mediterranean were acquainted with the magnetic needle, and knew how to make use of it more than a century before the time of Gioia.

Albert, surnamed the Great, in his treatise De Mineralibus, ^[6. Lib. ü. tract. 3, cap. 6. ] mentions a passage of a work, erroneously attributed to Aristotle, which he renders in these terms: Angulus magnetis quidam est, cujus virtus apprehendendi ferrum est, ad zoron, hoc est, septentrionalem; et hoc utuntur nautee: angulus vero alius magnetis illi oppositus trahit ad aphron, id est, polum meridionalem. Whether this remarkable passage be found in Aristotle or not is of little importance with reference to the period when Albert lived the was born in 1193, and died in 1280); indeed it is necessary to go farther back than his time, for the citation must have been made from some work still more ancient; and even if the treatise De Mineralibus were not the work of Albert, this would not diminish the importance of the passage which the author, whoever he may be, has therein inserted, and which not only shows that the directive power of the magnet was then known, but that this power was applied by mariners for the purposes of navigation. Besides, the same text is cited by Vincent of Beauvais, in the first part of his Bibliotheca Mundi; ^[7. Lib. ii. cap. 19. ] and this part, entitled Speculum Naturale, must have been completed in the year 1250, as appears from book xxvii. chapter 102. Brunetto Latini, in his Trésor, composed first in French (Paris, 1260), and then translated by himself into Italian, also speaks of the compass in language not to be mistaken.^[8. His words are, “Pour ce nagent le mariniers à l’enseigne de ces deux étoiles que l’on appelle Tramontaines et chacun des deux faces [de l’aimant] aise la pointe de l’aiguille à celle tramontaine à que cette face gist.” (Tritor, lib. i. cap. 113.) ] There is another text which has also become famous in this discussion; we mean that of the Bible-Guyot, from verse 622 to verse 658, in which we find the compass clearly indicated under the names of manière or marinière, manette or marinette, according to the various readings of the different manuscripts. This text may be seen entire in the Fabliaux and Contes, published by Barbazan and Méon.^[9. Tome ii. p- 327. It commences with these verses: De notre père l’apostoile volsisse qu’il semblast l’estoile Qui ne se muet... and it terminates with the following: ... Molt est l’estoile, et belle et cιeιe, Tiex devroit estre notre père. ] The satire, called the Bible-Guyot, is generally attributed to Guyot, a French monk of Provins, who must have flourished about the end of the twelfth century, since he appeared at the court of the Emperor Frederick I. in 1181. But supposing this rhythmical piece were, as some have thought, the work of Hugues de Bercy, a contemporary of Saint Louis, this difference would only bring down the date by fifty, or at the most sixty years. Lastly, a passage equally clear in the work of the Cardinal de Vitry, fixes the date beyond all doubt. James of Vitry, a native of Argenteuil, and bishop of Ptolémaïs in Syria, went to Palestine during the fourth crusade, that is, about the year 1204; on his return from this voyage, he discharged the functions of legate of Pope Innocent III. in the army which, in 1210, the Count de Montfort led against the Albigenses; and having again set out for the Holy Land, he returned thence under Honorius III. a considerable time before the death of this pope, and died in the year 1244. But if, as is commonly supposed, he wrote his description of Palestine, which forms the first book of his history, and is entitled Historia Orientalis, during his second sojourn in the East, this would fix its composition between the years 1215 and 1220; and, besides, he speaks of a fact which he had observed since the year 1204. Now, in his 91st chapter, he thus expresses himself: Acus ferrea, postquam adamantem contigerit, ad stellam septentrionalem, qiuε vel utaxis firmamenti, aliis vergentibus, non movetur, semper convertitur; unde valde necessarius est navigantibus in mari. [The iron needle, after contact with the loadstone, constantly turns to the north-star, which, as the axis of the firmament, remains immovable, whilst the other stars revolve; and hence it is essentially necessary to those navigating on the ocean.] The sense of these words presents no difficulty or obscurity. The question is not one relating to a new discovery, but to a usage already established, to an instrument regarded as absolutely necessary to mariners, to a species of knowledge which had in fact become general and common.

As Albert the Great, Guyon, and the Cardinal de Vitry, were all Frenchmen, and as Brunetto Latini composed his work during his stay in France, whilst James of Vitry must [7:10:527]have crossed the Mediterranean in French vessels, the Benedictine authors of the Literary History of France have thence concluded that the compass is a French invention; and, in support of this conclusion, they have referred to the usage (undoubtedly French) adopted by all nations of tracing upon the card of the compass a fleur-de-lis to indicate the north. This opinion has been adopted by Μ. Azuni, and maintained by all the means which extensive erudition could supply, in the dissertation to which we have already referred. But other writers have claimed for the Arabians the honour of this invention. Amongst these may be mentioned Tiraboschi, in his Storia della Letteratura Italiana ; Andres, in his Origine e Progressi d’ogni Letteratura ; Bergeron, in his Abrégé de l’ Histoire des Sarrasins; and Riccioli, in his Geographia et Hydrographia reformata. All the writers who have maintained this opinion, however, rest solely upon vague assertions, and are unable to produce any positive proofs. On the other hand, Chardin is persuaded that the Arabians received the compass from Europe; whilst Renaudot has gone so far as to maintain that there exists not any Arabian writing in which mention is made either of the compass, or even of the di.- rective virtue of the magnet.^[10. Anciennes Relations des Indes, p. 288, 291. ] Nor has any authority been produced against the latter opipion, except the work of Bailak Kaptchaki, entitled, in Arabic, Treasure of Merchants in the knowledge of Stones;^[11. • Bibliothèque Royale des Manuscrits, No. 970, in folio. ] and the passage of this writer, originally discovered by Μ. Silvestre de Sacy, confirms the opinion of Renaudot rather than destroys it, since the author, who wrote in the year 681 of the hegira, relates a fact of which he had been witness in the year 640 [ 1242 of our era], and since these dates are posterior to the times of Guyot de Provins and Cardinal de Vitry. Ebn-Iounis, an Arabian astronomer, in his Grand Hakemite Table, a work composed in the year 1007 of our era, and published in French by Μ. Coussin,^[12. Notices des Manuscrits de la Bibliothèque Royale, tome vii. ] also furnishes a negative proof of the most conclusive kind that the Arabians of his time were unacquainted with the compass; for neither among the instruments of which he makes mention, nor among the observations which he records, does he ever speak of or allude to such a thing in any way. But there always remains between these two epochs, that is, between the year 1007 and the year 1290, the passage attributed to Aristotle, which must necessarily have been derived from some Arabian author.

The authors who have written on China have attacked the claims of Gioia with most success. Father le Compte, Mailla, Father Gaubil in his Histoire de ĩ Astronomie Chinoise, and Barrow in his New Voyage to China, declare themselves convinced that the Chinese made use of the compass long before our era. Hager, in a dissertation published in Italian, under the title of Memoria sulla Bussola orientale, has developed this opinion, and endeavoured to prove not only that the compass is an invention of the Chinese, but that this people transmitted it to us by means of their communications with the Arabians. On this hypothesis, it appears wonderful that the compass, said to have been in use in the Indian Sea one or two thousand years before Christ, should not have been known either to the Egyptian navigators under the Ptolemies, or to the Greeks of Constantinople in the middle ages. Chardin had left the question in doubt. But Μ. de Guignes goes farther, and maintains that the sources whence Father Gaubil derived his information are modem romances; and he censures that historian for having supposed that he had detected the mention of a compass in texts which are recognised as fabulous.^[13. Mémoires de la Académie des Inscriptions, tome xlvi. p. 549, 551, ] Nevertheless, it cannot now be doubted that the Chinese were acquainted with the compass, if not at the early epochs of which Father Gaubil speaks, at least long before the Europeans; and great weight has been given to this opinion by the judgment which Barrow, Macartney, and other recent travellers, have formed on the subject.

But be this as it may, the writers who have attributed the invention to Gioia are innumerable. Amongst others, Grimaldi, a learned Neapolitan, has collected in favour of his countryman, in the dissertation which we have already cited, a number of positive authorities, and has supported them with very imposing names. Nor can it be dissembled that, during a long period, the opinion of all Europe supported the claim of Gioia, and that there must have been some important fact or circumstance to produce an assent so general in his favour. What, then, is the precise title which the mariner of Amalfi possesses to public gratitude? Father Fournier appears to have resolved this problem in his Hydrographie; ^[14. Liv. xi. chap. L ] and Montucla, adopting the opinion of Fournier, has developed it with a clearness calculated to satisfy every mind. The compass used in the Mediterranean during the twelfth and thirteenth centuries consisted only of a magnetic needle, which was made to float in a vase or bason by means of two straws or a bit of cork, which supported it on the surface of the water. Such is the description which the author of the Bible-Guyot has given of the instrument; and hence the names of calamite or of grenouille (frog), under which it is designated in some authors. The compass known to the Arabians, in the thirteenth century, according to Bailak Kaptchaki, was no other than that here described. “It is easy to perceive,” says Montucla, “how inconvenient this was, and how often the agitation of the sea would render it useless But the

Amalfitans imagined the convenient suspension which we now employ, by placing a magnetised needle on a pivot which permits it to turn to all sides with facility. It is not known that at first they went farther than this. Afterwards it was attached to a card divided into thirty-two points (rumbs de vent), and named Bose des Vents ; and then the box containing it was suspended in such a manner that, whatever motion the vessel might experience, it would always remain horizontal. The English claim, jure an injuria, this addition to the compass, but on what ground I know not, having seen no proof in support of such a pretension.” If the import of the verse of Antonius Panormitanus, which is considered as one of the strongest proofs in favour of the claim of Gioia, be examined with attention, it will perhaps be observed that allusion is made, not to an invention, but a great and important improvement. The verse in question is as follows:

Prima dedit nautis usum magnetis Ãmalphis.

The poet does not appear to affirm that the town of Amalfi had given to mariners the knowledge of the magnetic needle, but only that it had given, or rather facilitated, the usage thereof.

Such, then, appears to have been the merit of Gioia, namely, having rendered truly useful an instrument of which, though previously known in an unimproved state, little or no use could then be made. The timidity of pilots, in the twelfth and thirteenth centuries, when they were already in possession of the calamite or grenouille, and the boldness which they displayed when provided with the compass of Amalfi, evidently attest the importance of the service rendered to modern navigation by Gioia. To improve in this manner is really to invent. It is possible that the French may have added the Rose des Vents, or card, to the suspended needle of Gioia, which would account[7:10:528] for the fleur-de-lis being employed to indicate the north, as already mentioned. It is also possible that the English may have conceived the idea of including the needle, its pivot, and the card, in a box or boxel, whence probably the names of bussola and boussole. The Germans, moreover, claim the names of the winds, East, South, North, West, and even the name of the compass. But these particularities are of little importance. What appears to be established is, that the discovery of the directive virtue of the magnet was made anterior to Gioia; that, before hi* time, navigators both in the Mediterranean and the Indian Seas employed the magnetic needle; but that, by a very important improvement, in the suspension of the needle, Gioia is entitled to be considered as the real inventor in Europe of the compass such as we now possess it. No history of the life of this navigator is known. Some writers call him Giri; but the name of Gioia is that most generally adopted. Musanzio, in his Tables Chronologiques, complains that Vossius and other learned men call him Giri, and describe him as a native of Melfi, “instead,” says he, “of Gioia of Amalfi, who invented the compass in the year 1303.”^[15. Table xxxviii. p. 319. ] {Biographie Universelle.) (a.)