Philip Beeley and Christoph J. Scriba (eds), Correspondence of John Wallis (1616–1703), Vol. 4: 1672–April 1675
161.Wallis to Henry OldenburgOxford, 20/ March 1673/4
W Letter sent: London Royal Society Early Letters W2, No. 19, 2 pp. At top of p. 1 in Oldenburg's hand: 'Dr Wallis to Mr Oldenburg concerning the |4th add.| part of Mr Huygens Book de Motu Rendulorum, which is de Centro Oscillationis.' and: 'Ent⟨ere⟩d LB. 7. 46.' On p. 2 beneath address in Oldenburg's hand: 'Rec. March 23. 1673/74. Answ. March. 24. 73/74. and sent Mr Jessops letter and figures, herein mention'd; and promised to show Lord Brouncker his except (ions) against Hugens.' and at 90°: 'Wallis contra Hugens'. Postmark partly illegible: 'MR/–'.—printed: Oldenburg, Correspondence X, 525–7.
w1 Copy of letter sent: London Royal Society Letter Book Original 7, pp. 46–7.
w2 Copy of w1: London Royal Society Letter Book Copy 7, pp. 66–8.
Answered by: Oldenburg–Wallis 24.III/[3.IV].1673/4.
This letter, in which Wallis argues that he had anticipated some of the results recently published by Huygens in his a Horologium oscillatorium, was read at the meeting of the Royal Society 9 April 1674 (old style). See Kaye, Unrecorded early meetings, 151.
6Oxford March 20. 1673./4.
2I have heard nothing994 from you since I gave you an account995 of Mr 3Jessops last letter, what he says about it. His first letter996, which hath given 4the occasion to all the rest, I have no copy of, & therefore must desire it of Critical Apparatus5you997. I hope my last cannot but satisfy him; sure it satisfies his Objections 6fully; & so had my former allso, if he had apprehended them aright.
7I have since been reading M. Hugens his pars quarta, De Centro Oscilla-8tionis. He says998 of it (pag. 91.) Qui rem sese confecisse sperabant Cartesius, 9Fabrius, aliique, nequaquam scopum attigerunt. &c. Whether amongst his 10alii he means me or not, I am not certain; but I think he doth. Yet what he 11brings, is, in effect, but just the same with mine put into another dress, & 12spun into length. In my Cap. 11. De Motu, (which is, De Percussione,) prop. 1315. I had shewed the way how to calculate the Centrum Virium or Centrum 14Percussionis; and (that I might not tediously repeat what had been delivered 15before) after I had shewed999 the method of it in divers examples; I say1000 16(in the beginning of the Scholium) that from the Centrum gravitatis of the 17figure, to collect the Centrum Percussionis, was but just the same thing, as, 18from the Centrum Gravitatis of a Plain, to collect the Centrum Gravitatis of 19its Ungula, or Cuneus: Of which I had discoursed1001 at large in the 2d part, 20to which I there refer. And in the close1002 of that Scholium, That this Cen-21trum Percussionis or Virium, is that same point with Centrum Vibrationis, 22or (as he calls it) Centrum Oscillationis. And he doth so little disguise my 23methode, that (in his Def. 14, 15, Prop. 7. & what follows1003,) he expresselypg 368 1hath recourse to my Ungula, (& pursues the notion just as I had shewed;) 2onely he changeth the name, & what I had called Ungula he calls Cuneus, 3like as what I had called Centrum Virium, seu Percussionis, he calls Cen-4trum Oscillationis, seu Agitationis. And though he tell us1004 then (pag. 91.) 5that he hath melioribus auspiciis overcome the difficulty, and ex certioribus 6principiis, & that others nullam demonstrationem attulerunt; I do not find 7that he hath done it either with better success, or, from more certain prin-8ciples, or by better demonstrations. For I deduce all from the nature of the 9Libra, by considering the Momenta or librae Gravamina, in this case, to be, 10not barely the Pondera, but the Pondera celeritate gravata; & that the Cen-11trum Virium (which he calls Centrum Oscillationis) is nothing but horum 12Gravaminum centrum Aequilibris; & what he calls Linea Centri (which is, 13for the most part, if not allways in his discourse, the same line with his Axis 14gravitatis) is my Libra who's Gravamina are the Pondera celeritate gravata. Critical Apparatus15'Tis true, he speaks (in four or five of his first propositions) of new Principles 16(as he calls them;) but neither so clear, nor so well received as those of the 17Libra; nor are his any further sound, than as they are coincident with these.| 
18But I the less wonder at him in this, because I find the same in his 19second part1005, which is De Descensu Gravium; where the greatest part is 20but the same for Substance, which I had before delivered in my Cap. 21006. 21&c. But since he hath drawn in the Air of France, it is (it seems) below him 22to acknowledge any thing done by any body else: which while he was but a 23Dutch-man he was wont to do.
- 24 I adde no more, but that I am
- 25Your very humble servant,
- 26John Wallis.
27One word more. I remember that some while since, looking over a letter1007 28of mine which you sent1008 a Copy of (as I remember) to Monsieur Justell, 29(which concerned a Printed letter of Monsieur Fermat,) I saw reason to makepg 369 Critical Apparatus1some alterations1009; but I did not then think it necessary to give notice of 2that to M. Justel or those in France. But hearing that M. Frenicle is now 3about publishing somewhat1010 of such a subject, I know not but he may Critical Apparatus4make ill use of my paper. I think it not amisse if you civilly desire of M. Justel 5to send you that paper back again, to review; with promise to return it him 6again: You need onely mention, that understanding that in several copies 7of that letter there was some difference; you are willing to see whether that 8which he hath be according to the most corrected copy; &, if not, to return 9it him corrected: the Author having never seen the copy which was sent him. 10My letter, was of some sheets of paper, directed to my Lo. Brounker, about 11the year 1670, but (I think) without date.
- 13For Mr Henry Oldenburg,
- 14in the Palmal near St James's
16Since I wrote this, I have yours1011 of the 19th instant.