Letter to Edmund Halley on work on ellipses and the descent of falling bodiesIsaac Newtonc.547 wordsThe Newton ProjectFalmer2014Newton Project, University of Sussex
This text is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
14 July 1686, in English, c. 557 words, 2 pp.2 pp.
in English
Published in H.W. Turnbull (ed), The Correspondence of Isaac Newton, vol. 2 (Cambridge: 1960), p. 444
EL/N1/56, Royal Society Library, London, UKUKLondonRoyal Society LibraryEL/N1/5614 July 1686EnglandEnglishHolographEdmund HalleyUnknown Cataloguer (1)Unknown Cataloguer (2)MathematicsCorrespondenceTranscription by Daniele CassisaCode audited by Michael Hawkins
5656
July 14. 1686.
SrSir
I have considered yoryour proposal about wooden cuts & beleive it will be much convenienter for yethe Reader & may be sufficiently handsome but I leave it to your determination. If you go this way, then I desire you would divide yethe first figure into these two. I crouded ymthem into one to save yethe trouble of altering yethe numbers in yethe schemes you have. I am very sensible of yethe great kindness of yethe Gentlemen of your Society to me, far beyond wtwhat I could ever expect or deserve & know how to distinguish between their favour & anothers humour. Now I understand he was in some respects misrepresented to me I wish I had spared yethe Postscript in my last. This is true, that his Letters occasioned my finding the method of determining Figures, wchwhich when I had tried in yethe Ellipsis, I threw the calculation by being upon other studies & so it rested for about 5 yeares till upon your request I sought for ytthat paper, & not finding it did it again & reduced it into yethe Propositions shewed you by Mr Paget: but for yethe duplicate proportion I can affirm ytthat I gathered it from Keplers Theorem about 20 yeares ago. And so SrSir Christopher Wren's examining yethe Ellipsis over agtagainstyethe Focus shews ytthat he knew it many yeares ago before he left of his enquiry after yethe figure by an imprest motion & a descent compounded together. There was another thing in Mr Hooks letters wchwhich he will think I had from him. He told me ytthat my proposed exptexperiment about yethe descent of falling bodies was not yethe only way to prove yethe motion ofyethe earth & so added yetheexptexperiment of yoryour Pendulum Clock at St Hellena as an argumtargument of gravities being lessened at yethe equator by yethe diurnal motion.The exptexperiment was new to me but not yethe notion. For in ytthat very paper wchwhich I told you was writ some time above 15 yeares ago & to yethe best of my memory was writ 18 or 19 years ago, I calculated yethe force of ascent at yetheEquator arising from yethe earth's diurnal motion in order to know what would be yethe diminution of gravity thereby. But yet to do this business right is a thing of far greater difficulty then I was aware of. A third thing there was in his letters, wchwhich was new to me & I shall acknowledge it if I make use of it. 'TwasIt wasyethedeflexion of falling fbodies to yethe south east in orour Latitude. And now having sincerely told you yethe case between Mr Hook & me I hope I shall be free for yethe future from yethe prejudice of his Letters. I have considered how best to compose yethe present dispute & I think it may be done by yethe inclosed Scholium to yethe fourth Proposition. In turning over some old papers I met with another demonstration of that Proposition, wchwhich I have added at yethe end of this Scholium. Which is all at present from
YorYour affectionate Friend & humble Servant
Is. Newton.
Mr Newton July. 14 1686
LresLetters from Mr Newton Aug. 20. July. 14. Octob. 18