'S Gravesande's and Van Musschenbroek's Appropriation Of

chapter 8 ’s Gravesande’s and Van Musschenbroek’s Appropriation of Newton’s Methodological Ideas

Steffen Ducheyne

1 Introduction

Willem Jacob ’s Gravesande (1688–1742) and Petrus van Musschenbroek (1692–1761) are rightfully considered as important trailblazers in the diffu- sion of Newtonianism on the Continent.1 They helped to establish teach- ing of Newton’s natural philosophy within the university curriculum and the textbooks which they wrote were of vital importance in its spread and popularization.2 On the face of it, there are good reasons for portraying ’s Gravesande and van Musschenbroek as “Newtonians”. Both ’s Gravesande and van Musschenbroek spent time in England where they became acquainted

† Parts of this chapter was presented at the international conference “The Reception of Newton” (Edward Worth Library, Dublin, 12–13 July 2012). The author is indebted to its au- dience for useful suggestions. In this chapter I draw extensively on material from Steffen Ducheyne, “W.J. ’s Gravesande’s Appropriation of Newt on’s Natural Philosophy, Part i: Episte- mological and Theological issues”, Centaurus, 56(1) (2014), 31–55; id., “W.J. ’s Gravesande’s Ap- propriation of Newton’s Natural Philosophy, Part ii: Methodological Issues”, Centaurus, 56 (2) (2014), 97–120; id., “Petrus van Musschenbroek and Newton’s ‘vera stabilisque Philosophandi methodus’”, Berichte zur Wissenschaftsgeschichte, 38 (4) (2015), 279–304; and id., “Petrus van Musschenbroek on the scope of physica and its place in philosophy”, Asclepio, Revista de his- toria de la medicina y de la ciencia, 68, no. 1 (2016) article no 123. 1 John Gascoigne, “Ideas of Nature”, in Roy Porter (ed.), The Cambridge History of Science, Vol- ume 4: Eighteenth-Century Science (Cambridge: Cambridge University Press, 2003), 285–304; 297–299; Edward G. Ruestow, Physics at Seventeenth and Eighteenth-Century Leiden: Philoso- phy and the New Science in the University (International Archives of the History of Ideas se- ries, vol. 11 The Hague: Martinus Nijhoff, 1973), Chapter 7; and Pierre Brunet, Les physiciens Hollandais et la méthode expérimentale en France au XVIIIe siècle (Paris: Albert Blanchard, 1926), Chapter 1. 2 See, for instance, Cornelis de Pater, “The Textbooks of ’s Gravesande and van Musschenbroek in Italy”, in C.S. Maffioli and L.C. Palm (eds.), Italian Scientists in the Low Countries in the 17th and 18th Centuries (Amsterdam: Rodopi, 1989), 231–241 and Brunet, Les physiciens Hollandais, Chapter 2.

Newton’s Methododological Ideas 193 with Newton, his natural philosophy, and his disciples. In 1715 ’s Gravesande was secretary of a Dutch embassy which was sent to England to honour the coronation of George i and to negotiate about the barrier towns.3 During his stay, he was introduced to England’s leading natural philosophers: Isaac New- ton (1642–1727), who was president of the Royal Society at the time, the Royal Society’s curator of experiments, J.T. Desaguliers (1683–1744), and the Savillian Professor of Astronomy at Oxford, John Keill (1671–1721). In June 1715, ’s Graves- ande was elected Fellow of the Royal Society and during his stay in England he was won over by the Newtonian cause, the story goes. Shortly after his return, in 1717, he became professor of mathematics and astronomy at the University of Leiden, where he taught Newton’s natural philosophy until his death. His magnum opus carried the telling title Physices elementa mathematica experimentis confirmata, sive introductio ad philosophiam Newtoniam (first edition: 1720–1721; second edition: 1725; third edition: 1742).4 His counterpart, Van Musschenbroek, descended from a family of instru- ment makers, had obtained his doctoral degree in medicine from the University of Leiden in 1715, before receiving appointments at the University of Duisberg (1719–1723), where he obtained a doctoral degree in philosophy in 1719, and at the University of Utrecht (1723–1739), where he was professor of philosophy and mathematics and from 1732 professor of astronomy as well.5 In 1717 van Musschenbroek had, like ’s Gravesande before him, travelled to London to at- tend Desaguliers’ lectures on experimental philosophy and had met Newton. During his stay in England he came to accept the basics of Newton’s natural philosophy and the theory of universal gravitation. By 1740 he was professor of

3 Jean-Nicolas-Sébastien Allamand (ed.), Oeuvres philosophiques et mathématiques de Mr.G.J. ’s Gravesande 2 vols (Amsterdam: Marc Michel Rey, 1774 [1744]), I, xxi–xxii. 4 Willem Jacob ’s Gravesande, Mathematical Elements of Natural Philosophy, Confirm’d by Experiments : Or, an Introduction to Sir Isaac Newton’s Philosophy, tr. J.T. Desaguliers, 2 vols; (6th edn., London: Printed for T. Longman e.a., 1747 [1720–1721]) and id., Physices elementa mathematica experimentis confirmata, sive introductio ad philosophiam Newtoniam, 2 vols (3rd edn. Leiden: Johann Arnold Langerak, Johann and Hermann Verbeek, 1742 [1720–1721]). I will rely on the above editions throughout this essay. 5 On the cooperation between Petrus van Musschenbroek’s older brother Jan and ’s Graves- ande, see Anne C. van Helden, “Theory and Practice in Air-Pump Construction: The Coopera- tion between Willem Jacob ’s Gravesande and Jan van Musschenbroek”, Annals of Science, 51 (5) (1994), 477–495. For van Musschenbroek’s biographical details I have relied on Cornelis de Pater, “Petrus van Musschenbroek (1692–1761), Een newtoniaans natuuronderzoeker”, Ph.D. diss. (Utrecht University, 1979), 24–28. More information about links between Newtonian- ism and the practical tradition of Dutch philosophy may be found in Gerhard Wiesenfeldt’s paper in this collection.