Letter from Henry Oldenburg to Newton, dated 2 May 1672 Henry Oldenburg c. 514 words Newton Project London 2011 Newton Project, University of Oxford

This metadata is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

 2 May 1672, c. 514 words. MS Add. 3976, ff. 10r-11v, Cambridge University Library, Cambridge, UK UKCambridgeCambridge University Library MS Add. 3976, ff. 10r-11v 2 May 1672 England English Latin French Holograph Unknown Cataloguer ScienceCorrespondence ScienceOpticsCorrespondence Catalogue information compiled by Rob Iliffe, Peter Spargo & John Young Catalogue exported to teiHeader by Michael Hawkins Transcribed by Robert Ralley. Add. 39766d[10]

London May 2. 72.

Sir,

Having sent away yryour answer to yethe Iesuit Pardies, after it had been read at our Society as well as yryour letter containing yryour observations relating to SrSir R. Moray's proposals; I receiued a printed account from Paris, wchwhich relateth to yryour Telescopes, and pretends to haue lighted upon a refinemtrefinement of ytthatymthem. This I thought myself obliged to impart it to you, ytthat you mayight consider it, and compare it wthwith what Mr Gregory, the Scot, hath printed concerning it, in his optica promota Ann. 1663 pag. 92. 93. 94: and thereupon let me know what answer to return to those Parisian Refiners; who speake thus:

Il y a environ mois, que M. Cassegrain a communiqué la figure d'un Telescope, qui est presque semblable à celuy de M. Newton, et qu'il a inventé; mais que ie trouue plus spirituel. Ie vous en fais icy la description.

ABCD est vn fort tuyan, dans le fonds duquel il y a un grand miroir Concave Cd, percé en son milieu.

F est un miroir convexe, desposé de telle maniere, eu esgard à sa convexité qu'il refleschit les especes, qu'il recoit du grand miroir, vers le trou au milieu dc Cd; ou'il y a un Oculaire, au travers duquel on regarde.

L'avantage, quei se trouue dans cet Instrument sur celuy de M. Newton, est, 1. que l'embouchure ou l'ouuerture du luyan AB, peut estre de telle grandeur qu'on vendra; et par consequent que l'on aura bien plus de rayons sur le miroir concaue, que sur celuy de M. Newton. 2. La reflexion des rayons sera tres naturelle, puisqu'elle se fera sur l'Axe mesure, et consequemment plus vive. 3. La vision en sera d'autant plus agreable, qu'on ne sera ponit incommo, de' du grand iour, à cause du fond CD, qui couvre tout le visage. Outre qu'on aura monis de peine à descouvrir les Objects, que dans celle de M. Newton.

So far the French Iournal. I am of opinion, you will find cause to controle these confident assertions of theis Author, as I am apt to belieue, you will make good yryour Theory of light; wchwhich some begin to lay more weight upon now, than at first. Howeuer, I shall suggest, ytthat when your answer to Mr Hooks and yethe Iesuit Pardies objections shall be thought fit to be printed, yethe names of the Objectors, especially if they desire it may be so, be omitted, and their objections only red and urged: since those of the R. Society aime ought to aime at nothing, but the discovery of truth, and yethe improvemtimprovement of knowledge and not at all the prostituting of persons for their mis-apprehensions or mistakes. of s

Our Treasurer was not present at our meeting; so ytthat I could not deliuer him yryour quarters paymtpayment: wchwhich I shall doe the first time I find him there; and then send you his acquittance; being

Sir

yryour faithful servtservant

Oldenburg.

To his honor'd friend Mr Isaac Newton Professor of the Mathematicks, in Trinity Colledge in the University of

Cambridge

2