Dictionary of National Biography, 1885-1900/Magellan, Jean Hyacinthe de
MAGELLAN or MAGALHAENS, JEAN HYACINTHE de (1723–1790), scientific investigator, was lineal descendant of the great Portuguese navigator, Ferdinando Magalhaens, who discovered in 1520 the passage to the Pacific Ocean through the straits bearing his name. He is said, indeed, to have been the navigator's great-grandson, but this is quite impossible (cf. Gent. Mag. 1790, pt. i. p. 184). He is also claimed as a near relative of Gabriel Magalhaens and of Antonio Magalhaens. The former, a well-known jesuit missionary, travelled over China from 1640 to 1648, till he was carried to the court of Pekin, where he resided till his death in 1677. The latter, Antonio Magalhaens, accompanied the papal legate, Mezzabarba, from China to Rome in 1721–6. De Magellan signed his letters ‘Jean Hyacinthe de Magellan,’ but his proper name was João Jacinto de Magalhães (see Biog. Universelle, xxvi. 113). Although Lisbon was his reputed birthplace, there is reason for supposing that he was born at Talavera in 1723. On the title-page of his translation of Cronstedt's ‘System of Mineralogy,’ 1788, he assumed the appellation ‘Talabrico-Lusitanus’ (ib. p. 120). He seems to have been brought up at Lisbon, where he became a monk of the order of St. Augustine, and was pursuing his studies in the Portuguese capital when the city was destroyed by the great earthquake of 1755, an event which he could never recollect without shuddering (Monthly Review, lix. 140). Magellan obtained a wide reputation as a student of chemistry and mineralogy and other branches of natural science. When forty years old he abandoned the monastic life in order to devote himself to wider philosophical research. About 1764 he appears to have reached England and was in communication with Da Costa of the Royal Society in 1766 (see Nichols, Illustrations of Literature, 1831, vi. 498), but for some time he acted as tutor to various young foreigners of distinction on continental tours, an occupation for which his powers as a linguist, in Latin and almost all modern European languages, specially fitted him. While travelling on the continent he made the acquaintance of the leading scholars of the day, especially in the Netherlands. ‘All the Literati in Europe knew something of his merit, and the most noted of them were desirous to know more’ (Gent. Mag. l.c.)
Magellan was elected a fellow of the Royal Society in 1774, and was a corresponding member of the academies of science in Paris, Madrid, and St. Petersburg. His book on English reflecting instruments, published in Paris and London, 1775, was declared by Lalande (Bibl. Astron.) to be the most complete work on the subject at that period. In June 1778 Magellan was at Ermenonville, the seat of the Marquis de Gerardin, and there, with M. du Presle, visited Jean-Jacques Rousseau a few days before his death on 2 July. He added a postscript describing his visit to Du Presle's ‘Relation des derniers Jours de J. J. Rousseau,’ London, 1778. Magellan definitely settled in London soon afterwards. He still maintained an animated correspondence with the chief French, Italian, and German physicists, and endeavoured to establish a system by which they might communicate to one another the results of their investigations of special subjects. He was for some time engaged in superintending the construction of a set of astronomical and meteorological instruments for the court of Madrid, which he described in 1779; and he also published descriptions of apparatus for making mineral waters and of some new eudiometers for testing respirable air.
He devoted his last years to perfecting the construction of instruments for scientific observation, such as thermometers and barometers, &c. Among the most notable of his mechanical devices was a clock which he made for the blind Duke of Aremburg, which indicated by the strokes of various bells the hours, half-hours, quarters, and minutes, the day of the week, of the month, of the moon, &c.
Among Magellan's friends was the Hungarian Count de Benyowsky. About 1784 the count borrowed a large sum of Magellan, and was soon afterwards shot as a pirate by the French in Madagascar. Magellan gave the count's memoirs to William Nicholson, who published them in English in 1790. Magellan's French version of the memoirs appeared after his death, and the latest letters of Magellan to Benyowsky were published in the Hungarian writer Jokai's new edition of the count's memoirs. Magellan never recovered the money lent to the count, and suffered much from the loss. He died on 7 Feb. 1790, after more than a year's illness. He was buried in Islington churchyard, having many years previously renounced the Roman catholic religion. ‘His height was about six feet two inches, a bony and rather bulky man, plain in his dress, unaffectedly mild and decent in his whole demeanour.’
Magellan's chief works are: 1. ‘Collection de différens Traités sur des Instrumens d'Astronomie,’ &c., 4to, 1775–80. 2. ‘Description des Octants et Sextants Anglois,’ dedicated to Turgot, 1775. 3. ‘Description of a Glass Apparatus for Making Mineral Waters,’ &c., 1777; 3rd edit. 1783. 4. ‘Description et Usages des nouveaux Baromètres pour mesurer la Hauteur des Montagnes et la Profondeur des Mines,’ 1779. 5. ‘Essai sur la nouvelle Théorie du Feu élémentaire, et de la Chaleur des Corps,’ 1780. 6. ‘An Essay towards a System of Mineralogy,’ &c., 1788. 7. ‘Mémoires de Maurice Auguste, Comte de Benyowsky,’ &c. (posthumous), 1791. He also wrote various articles in ‘Journal de Physique,’ 1778–83.
[Gent. Mag. 1788 p. 77, 1790 p. 184, 1799 p. 434, 1818 pt. ii. p. 115; Nichols's Lit. Anecdotes, viii. 48 et seq.; Monthly Review, lix. 410; Dodsley's Annual Register, xxi. 132, xxxii. 196; Brit. Mus. Cat., art. ‘Magalhaens, João Jacinto de.’]