Max Planck Research Library for the History and Development of Knowledge Studies 7 Christa Jungnickel and Russell McCormmach: Science In: Christa Jungnickel and Russell McCormmach: Cavendish : The Experimental Life (Sec- ond revised edition 2016) Online version at http://edition-open-access.de/studies/7/ ISBN 978-3-945561-06-5 First published 2016 by Edition Open Access, Max Planck Institute for the History of Science under Creative Commons by-nc-sa 3.0 Germany Licence. http://creativecommons.org/licenses/by-nc-sa/3.0/de/ Printed and distributed by: PRO BUSINESS digital printing Deutschland GmbH, Berlin http://www.book-on-demand.de/shop/14971 The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available in the Internet at http://dnb.d-nb.de Chapter 3 Science De Moive Circle Technically speaking, Lord Charles Cavendish was a commoner, but he was nevertheless a member of the highest circle of the British aristocracy, and as such he had been brought up to the values of the aristocracy, including the principal value of “duty of service.”1 To an aris- tocrat such as Charles, the only acceptable form of occupation (aside from administrating, but definitely not farming, his property) was public service, usually either in government or in the military, or possibly in the church. It came down to a narrow but attractive choice of occupations. The Cavendishes had served in some of the highest offices at court and in the government for almost half a century, and Cavendish, as we have seen, followed their example as soon as he reached maturity. Other interests, in the arts, architecture, belles let- tres, various areas of scholarship, or natural science, no matter how expertly pursued, had to keep the outward appearance of an aristocrat’s private indulgence, at best to be shared with friends. Cavendish’s contemporary Lord Chesterfield made what many would have per- ceived as a sensible judgment for the time when he censored the architectural expert Lord Burlington for having more technical competence than his rank permitted.2 From the perspective of the larger society, Charles Cavendish, who was drawn to exper- iment and to the instruments of experimental science, would have been seen as overstepping the bounds of his station if he had allowed his experiments to take over his life. The occupa- tional limitations of the aristocracy almost certainly affected the way he worked in science and his scientific reputation, or lack of it. For many years he carried on scientific inves- tigations that were valued and used by other investigators, but he published only the one paper for which he received the Royal Society’s Copley Medal. He contributed publicly to science in the same manner in which he had served the government: as a “parliamentarian” of science, a member of the Royal Society who served on its councils and committees, and as a member of boards and committees of other organizations. As a result of this activity, he became one of the most important official representatives of science of his time in Britain, and its untiring servant. His qualifications were his scientific talent, practical ability, long parliamentary experience, and the Cavendish name. He was a good example of a kind of scientific practitioner who was useful in eighteenth-century British science but who did not survive into the later organization of science. In 1725, the year after he returned from his Continental tour, Cavendish became a Member of Parliament, as we have seen, but since he was so very young, completely inex- perienced, and relatively unknown, he entered slowly into the work of the Commons. As he 1John Cannon (1984, 34). 2Dorothy Marshall (1968, 219). 50 3. Science was also relatively free of family duties, he had time to continue his education. His teacher, or one of his teachers, was almost surely the talented mathematician Abraham de Moivre. De Moivre’s friend Matthew Maty drew up a list of his eminent mathematical friends3: Newton, Edmond Halley, James Stirling, Nicholas Saunderson, Martin Folkes, and, on the Continent, Johann I Bernoulli and Pierre Varignon. (To this list we add from other sources William Jones4 and Brook Taylor,5 and there were still others.) Maty also listed De Moivre’s friends and disciples, all former pupils of his: Lord Macclesfield, Charles Stanhope, George Lewis Scott, Peter Davall, James Dodson, and “Cavendish.” (The Lucasian Professor in Cambridge John Colson should be included among his pupils, and no doubt others who come up in this book.)6 Since Maty gave only last names, we must decide which “Cavendish” he intended. Writing in the late 1750s, Maty would not have meant Henry Cavendish, who had only re- cently come down from Cambridge and was not yet a fellow of the Royal Society. Nor was it likely that he had in mind William Cavendish, duke of Devonshire, whom in any case he would have called Devonshire instead of Cavendish. The judgment Maty wanted his readers to make was of De Moivre’s standing among accomplished mathematicians, not among un- knowns or persons not known to have had significant mathematical interests. There are two likely possibilities, Charles Cavendish and his uncle James Cavendish. Both were active in the Royal Society, and both were proposed for membership in the Society by De Moivre’s good friend, the eminent mathematician William Jones.7 Together with Devonshire, both also subscribed to De Moivre’s Miscellanea analytica de seriebus et quadraticus; published in 1730, which was the first mathematical or scientific book to which Charles subscribed. James Cavendish was born in 1678, and if he had been a pupil of De Moivre’s he would have belonged to a generation earlier than that of the pupils named by Maty, indicating Charles as the more likely pupil of De Moivre’s. Authors of a study of De Moivre’s “knowledge community” write that both Charles and his uncle James and also his father William “were all taught by De Moivre.”8 Among Charles’s papers, kept and labeled by his son Henry, is a group “Mathemat- ics.” Because of the likelihood that by “Cavendish,” Maty meant Charles Cavendish, and because of the evidence it provides of the mathematical education of the Cavendish family, we include the following brief discussion of De Moivre. De Moivre fostered a sense of con- nection between his pupils, evidently bringing them together at social evenings, and later keeping them “together as a kind of clique.” Maty kept track of their publications in his Journal Britannique,9 and they appeared together in the list of subscribers to De Moivre’s 3Matthew Maty (1760, 39). 4De Moivre called William Jones his “intimate friend” in the preface to his book The Doctrine of Chances; or, A Method of Calculating the Probability of Events in Play (London, 1718), x. 5De Moivre called Brook Taylor his “Worthy Friend” in his Doctrine of Chances, 101. His correspondence with Taylor is described in Ivo Schneider (1968, 196–197). 6In the foreword to his first book, Animadversiones, De Moivre referred to John Colson as one of his pupils, noted by Schneider (1968, 189). 7James Cavendish was proposed for membership in the Royal Society on 19 Mar. 1718/1719, and was admitted on 16 Apr. 1719, JB, Royal Society 11:311, 326. 8The likely intermediary who supplied De Moivre with a letter of introduction was one of two Huguenot friends, Abraham Meure or John Buissière. D.R. Bellhouse, E.M. Renouf, R. Raut, and M.A. Bauer (2009). Published online before print (25 Feb. 2009 http://rsnr.royalsocietypublishing.org/content/early/2009/02/23/rsnr.2008.0017. full). 9Uta Jannsens (1975, 17). Augustus De Morgan (1857, 341). 3. Science 51 republication of his mathematical papers.10 Through De Moivre, his pupils formed a living connection with great mathematicians and scientists of the recent past. The intermediary De Moivre was Newton’s junior by twenty-five years and Cavendish’s senior by about the same number of years. If we leave aside the foreigners named by Maty, we are directed to a select few mathe- maticians within the larger group of British mathematicians in the early eighteenth century with whom Cavendish came to be associated. For convenience, we will speak of a “De Moivre circle,” whose members give us an idea of the mathematical setting in which Charles Cavendish probably completed his education. The learned world of London had recently been enriched by an influx of Huguenots, Protestants forced by Louis XIV to leave France with the revocation of the edict of Nantes. Within the Cavendish family, as we have seen, the Ruvignys settled in Greenwich, home to the Royal Observatory, a prophetic location, and they encouraged other refugees to follow.11 De Moivre and his father, one of a number of Huguenot surgeons and physicians to seek asylum in England, were naturalized in 1687;12 Abraham was then twenty and an advanced student of mathematics. In De Moivre’s mind, his arrival in England was so closely identified with his discovery of Newton’s work that although two years elapsed between the two events, to him they seemed simultaneous. For biographers of Charles and Henry Cavendish, it is gratifying that De Moivre first encountered Newton’s work in the house of the earl of Devonshire. It was probably in 1689, when Newton spent a good deal of time in London as a member of the Convention Parliament for Cambridge, and when Devonshire enjoyed the fruits of the Revolution as a prominent politician in Parliament and at the court of William and Mary. De Moivre first saw Newton as he was leaving Devonshire’s house after presenting the earl with a copy of his Principia.