Credit: ©The Royal Society
    Image number: RS.15028

    Diagram of a cycloid

    Date
    5 July 1673
    Creator
    Unknown, Artist
    Object type
    Archive reference number
    LBC
    Manuscript page number
    vol6 p214
    Material
    Dimensions
    height (page): 301mm
    width (page): 177mm
    Subject
    Description
    Copy of a diagram of an 'imperfect' cycloid from John Wallis's marginal annotations in Francis Jessop's letter to Martin Lister dated 25 June 1673.

    In response to Jessop's comments on his theory of tides, Wallis explained that the imperfect cycloid did not have its base ba as the perpendicular to the curve ac (as Jessop supposed), but that the base ba was a tangent to the curve ac and perpendicular to it at ap, as shown here. Wallis originally made his comments in the margin of Jessop's letter dated 25 June 1673 and addressed to Martin Lister, who had forwarded it to Henry Oldenburg so that Wallis could comment on it. He repeated the point in his letter of 15 July 1673 (EL/W2/10/001). For Jessop's diagrams, see EL/I1/165/001.

    Francis Jessop (1638-1691) was a freeman of the Cutler's Company of Sheffield and a close friend of John Ray (Correspondence of Henry Oldenburg, vol. 10, p. 71n).

    This is copied from LBO/6/186.
    Object history
    Francis Jessop wrote to Martin Lister on 25 June 1673, commenting on John Wallis’s paper in Phil. Trans. vol. 1, no. 16 (1665) on the tides. This letter (The Correspondence of Henry Oldenburg, ed. by A. Rupert Hall and Marie Boas Hall, 13 vols (Madison: University of Wisconsin Press; London: Taylor and Francis, 1965-86), X (1975), 69-71 (no. 2262)) was sent by Lister to Oldenburg on 28 June 1673 (ibid., X, 69), who enclosed the original letter from Jessop to Wallis on 3 July 1673 (ibid., X, 74f. (no. 2267)). Wallis replied on 5 July 1673 to Oldenburg, returning Jessop’s letter with his annotations and emendation (ibid., X, 77 (no. 2270)). Wallis wrote again on 15 July 1673, EL/W2/10 (ibid., X, 86-88 (no. 2280)), repeating his reply that Jessop was right in assuming that the line used by Wallis was an imperfect cycloid, but that its base ba was a tangent to the curve ac, and perpendicular to it at ap (in the bottom figure).
    Related fellows
    Martin Lister (1639 - 1712, British) , Physician
    John Wallis (1650, British) , Mathematician
    Associated place
    <The World>
       > Europe
          > United Kingdom
    Powered by CollectionsIndex+/CollectionsOnline