Although not himself an investigator of nature, Magellan was immensely well-informed concerning comtemporarydevelopments in the exact sciences and chemistry. He acted as an intermediary between scholars, transmitting the latest scientific news, and as an agent for the supply of London-made scientific instruments and machines to savants and institutions throughout Europe. Most of his publications were descriptions, in French, of English scientific apparatus which while being valuable, popularising descriptions of new apparatus, also served as a form of trade catalogue.Among the scientific apparatus that Magellan had made in London on commission for institutions such as the University of Coimbra or savants such as Horace Bénédict de Saussure, are avery small group of small astronomical regulators. Apart from the example offered here, seven other specimens are known one of which was made for the Physics Collection of CoimbraUniversity, one for either the Observatory or the University of Geneva, and others for the observatories of Gdansk, Madrid, Florence and Helsinki. Despite minor variations in the layout of the dials, it is clear that all were engraved by the same hand and that all eight clocks are of the best London work. A further clock bearing Magellan's name, an adaptation of Franklin's 4-hour dial clock as described by James Ferguson (See Antiquarian Horology, IX, 1974, 99-100), is also signed by its maker Michael) Ranger (fl. 1774-1820) which may indicate that he was the chamber-master who made Magellan's other horological purchases. Be this as it may, all small regulators are rare, those of the 18th century especially so. This example by Magellan has the added interest of illustrating the export of English horology to the European mainland.Literature:- Arthur Birembaut, Sur les lettres du physicien Magellan conservées aux Archives Nationales, Revue d'Histoire des Sciences et leurs applications, ix, 1956, pp 150-61.- G. l'E. Turner, The Portuguese Agent, J. H. de Magellan, Antiquarian Horology, IX, 1974, 74-76.- Stuart Pierson in Dictionary of Scientific Biography, IX, 5-6.Jean-Hyacinthe de Magellan (1722-1790), was born at Aveiro, Portugal, and from the age of about eleven spent some twenty years in an Augustinian monastery in Coimbra. Here he learnt astronomy and physics to a more than rudimentary level, and in circa 1752/3 left the order. For some years he moved restlessly around Europe until he finally settled in England circa 1764 where in 1774 he was elected a Fellow of the Royal Society three years after his election as a corresponding member of the AcadémiRoyale des Sciences in Paris.Ferdinand Berthoud, (1727-1807), was a chronometer-maker born at Plancemont, near Neuchâtel, Switzerland, on March 19, 1727. From a very early age he showed interest in mechanical matters. His father therefore decided to have him taught clockmaking and, at the age of 14, Ferdinand was apprenticed to his brother Jean Henri. When he was 19, he went to Paris, where another brother, Jean-Jacques, a designer, was already established. It is thought that he worked for Julien Le Roy for some time.Ferdinand, uncle of Louis Berthoud and rival of Pierre Le Roy, established himself in Paris in the Rue de Harley, Ile de la Cité in 1745. In 1752 he presented to the Academy of Science an equation watch with a perpetual calendar. By order of the King, he went twice to England, with Camus and Lalande, to examine John Harrison's marine clocks but Harrison only let him see numbers 1, 2 and 3, not number 4. However, on his second trip to England in 1766, Berthoud obtained from Thomas Mudge the inforation he needed concerning Harrison's number 4, which allowed him to enlarge his own research.He then undertook the construction of his own marine clocks 6 and 8, which competed for the prize for the best way of measuring time at sea, proposed in 1767 and 1769 by the Académie Royale des Sciences. These timekeepers were tried at sea in 1768 and 1769 by Eveux de Fleurieu, commanding the frigate Isis, and, with those of Pierre Le Roy, in 1771 and 1772 by Verdun de la Crenne. Despite the influential support of Fleurieu, it was finally Pierre Le Roy who received the double prize of the Académe.During the course of his career, Berthoud received various official appointments among which: Horloger de la Marine (Clockmaker to the Royal Navy); Member of the Institute of France; Fellow of the Royal Society of London; and, Chevalier of the Légion d'Honneur.Berthoud made many experimental marine watches, most of which, purchased by the Government, are preserved in the Musée Nationale des Techniques (C.N.A.M.), Paris. They include watches and clocks with equation of time, seconds watches, and superb astronomical longcase clocks fitted with compensated pendulums which he invented. All the timepieces that he made show his great dexterity, and the exceptional quality of his execution. The details of their construction and the experiments he carried outwith the instruments are described in the numerous books that he published at government expense.The precision instruments that he invented enabled Berthoud to perfect a rigorous experimental technique, adopted by all his successors, and particularly by his nephew Pierre Louis Berthoud, who was also his pupil. Other chief pupils of his were Jacques and Vincent Martin.Ferdinand Berthoud, who had married twice, firstly Mademoiselle Chatri of Caen, and then Mademoiselle Dumoustier of Saint Quentin, died on 20 June 1807, in his property at Groslay, near Montmorency, leaving no children.