João Jacinto de Magalhães was born in the Portuguese town of Aveiro on November 4, 1722. He is better known to the English-speaking world by the name he published most of his works under, Jean-Hyacinthe Magalhães . He claimed to be a descendant of the Portuguese explorer, Fernão Magalhãaes (Ferdinande Magalhães , c. 1490 - 1521). At the age of eleven Magalhães 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 Magalhães became familiar with science, particularly astronomy. In 1751 Magalhães 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 Magalhães 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

Whereas Magalhães 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.

Magalhães' 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. Magalhães also contributed to A. G. Lebegue de Presle's work on Jean-Jacques Rousseau, and edited two works of A. F. Cronstedt. In addition, Magalhães 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. Magalhães' 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.

On September 17, 1785 Magalhães sent a letter to the American Philosophical Society inquiring if the Society would be willing to accept 200 guineas to establish a yearly scientific prize. The form of the Premium fit into the views of the Society's founder and then president, Benjamin Franklin, who viewed the awarding of medals and prizes as an appropriate custom for the new democratic Republic. Magalhães wrote that all he required was the reply of the Society, and he would send the 200 guineas by way of his friend Samuel Vaughan (APS member 1784). Benjamin Franklin personally wrote Magalhães on January 24, 1786 to accept the offer, and inform him that a committee had already been formed to establish rules for the award in accordance with his intentions. The Society had approved the Premium, with slight modifications to Magalhães 's conditions and the addition of astronomy to the categories. The APS carried an announcement of Magalhães 's offer in the next volume of its publication Transactions of the American Philosophical Society, vol. 2 (1786), which was followed by an advertisement for the award in Volume 3, 1793. In the 215 years since Magalhães offered the Premium, the APS has awarded only 32: twelve for navigation, twelve for natural philosophy, and eight for astronomy.

Later in life, Magalhães 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. Magalhães 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.

The João Jacinto de Magalhães Collection consists of eleven letters on optics and the manufacture of telescopes, all written by Magalhães in French. Addressed to Charles Messier (1774-1776), Baudouin de Guemadeuc, and the Abbæ L. Garrellon of the monastery at Molesme (1783-1788), these make mention of the colleagues including William Herschel (1738-1822), and Ruggero Giuseppe Boscovich (1711-1787), and the instrument makers Peter Dollond, and John Edwards. Discussing reflecting and Newtonian telescopes, the need for quality flint glass, optics, and other topics, the collection offers insight into the manufacture and distribution of scientific instrumentation in the late 18th century.

None.

The Magalhães Collection was purchased in 1984 with funds provided by the Friends of the American Philosophical Society Library.

Cite as: João Jacinto de Magalhães Collection, American Philosophical Society.

Recatalogued by J. J. Ahern, 2002.

Eleven letters to or from Magellan are located in other APS collections. These include:

APS Archives	1783 June 17	Magalhães to Secretary of the APS
	1783 October 18	Bond, Thomas to Magalhães
	1785 December 21	List of books sent to APS
	1785 September 17	Magalhães to president and members of the APS
	1786 July 7	Magalhães to president and members of the APS
Fabbroni Papers (B F113)	1778 August 26	Walsh, [John?] to Magalhães
	1780 December 20	Magalhães to Fabroni, Jean
	1787 April 17	Magalhães to Fabroni, Jean
Franklin Papers (B F85.168)	1786 January 24	Franklin, B[enjamin] to Magalhães
Vaughan Papers (B V462.1)	1789 February 19	V[aughan], J[ohn] to Magalhães
Misc. Ms. Collection	1780 February 4	Magalhães to [Adam Fabroni]