Correspondence of Sir Isaac Newton and Professor Cotes : including letters of other eminent men, now first published from the originals in the library of Trinity College, Cambridge; together with an appendix containing other unpublished letters and papers by Newton; with notes, synoptical view of the philosopher's life, and a variety of details illustrative of his history, by J. Edleston.

  • Isaac Newton
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: Correspondence of Sir Isaac Newton and Professor Cotes : including letters of other eminent men, now first published from the originals in the library of Trinity College, Cambridge; together with an appendix containing other unpublished letters and papers by Newton; with notes, synoptical view of the philosopher's life, and a variety of details illustrative of his history, by J. Edleston. Source: Wellcome Collection.

    177/430 (page 71)
    In making these rules I take the measure of a degree at any point of the Meridian to be proportionable to ye Radius of the curvature of ye Ellipsis at that point, or which is ye same thing to be proportionable to ye Cube of y* part of the Radius of ye curvature which is intercepted between ye point proposed in ye Ellipsis & the point where the Radius intersects ye greater Axis; and ye angle made by that intersection I take for the measure of the Latitude. Thus 1 had then altered ye place, but I think this exact- ness is not necessary; for ye following terms of these series are inconsiderable in respect of the first, & the figure of the Earth is not exactly Elliptical & the solution of the Problem will be more simple without it, by taking ye length of ye Pendulum under the ./Equator to ye length under the Poles in the proportion of 229 to 230, & the Measure of a degree at the ACquator to ye measure at ye Poles in the triplicate proportion of 229 to 230 or as 228 to 231 or 76 to 77, & in both cases by making the increment from the AEquator to be as the square of ye sine of ye Lati- tude or as the versed sine of the doubled Latitude. As to the Table of the lengths of Pendulums & the measures of Degrees I beleive Your Readers would rather desire it were computed to ye difference of 32 Miles than to that of 17 Miles, & I do not see any use of it as it now stands for which the Table made to the difference of 32 Miles may not serve. If You agree to this Proposal, I will compute it as you shall direct either by the Series or the other way. It must be placed after Your account of the Observations & thereby some small changes will be made in the context which You may be pleased to send me. What I have further observed as to this Proposition is as follows. You have put down Gorese Latitudo 14°. 15'. by ye observations of Des Hayes tis 14°. 40'. In Your account of Picard’s experiment of an heated wire You say [in igne posita] De la Hire says only [car M: Picard ayant expose