Jean-Hyacinthe Magellan was born João Jacinto de Magalhães in the Portuguese town of Aveiro on November 4, 1722. At the age of eleven he went to an Augustinian monastery in Coimbra in which he spent the next twenty years living and studying, first as a novice and later as a monk. It was during this time that Magellan became familiar with science, particularly astronomy. In 1751 Magellan served as the guide during Gabriel de Bory's visit to Portugal to observe a solar eclipse. A few years later he decided to leave the monastic life in order to fully pursue scientific research. Between 1755 and 1764 Magellan traveled through Europe, serving as a tutor to various youths on continental tours, until finally settling in England. By 1766 he was in communication with several members of the Royal Society of England.
Drawing of Joshua Humphryes, Jr.'s steering apparatus
Whereas Magellan published few items of original work, his importance to modern scientific historians lies in the volumes of his correspondence with the internationally renowned scientists of his day. He was interested in the latest developments in chemistry and experimental physics, and became a link for the exchange of new information. He is credited with introducing English scientific instruments, and the work of Joseph Priestley (APS member 1785) to the scientific community in France.
Magellan's own work focused primarily on scientific instruments, his first publication Description des Octants et Sextants Anglois in 1775 was a description of English octants and Hadleyan (or reflecting) sextants. Magellan also contributed to A. G. Lebegue de Presle's work on Jean-Jacques Rousseau, and edited two works of A. F. Cronstedt. In addition, Magellan designed scientific instruments and mechanical devices - most notably a set of astronomical and meteorological instruments for the court of Madrid, and a clock for the blind Duke of Aremburg that indicated the time and day through various bells. Magellan's work and notoriety earned him membership in the Royal Society of England (1774) and the American Philosophical Society (1784), as well as corresponding membership in the academies of science in Paris, Madrid, and St. Petersburg.
Later in life, Magellan lent a large sum of money to his friend Count de Benyowsky of present day Hungary. A short time later Count de Benyowsky was shot by the French in Madagascar as a pirate. Magellan was never able to recover from this financial loss. He died on February 7, 1790 after a long illness and was buried in the Islington churchyard.