Credit: ©The Royal Society
    Image number: RS.15044

    Transverse scale for astronomical observation

    Date
    31 December 1673
    Creator
    Unknown, Artist
    Object type
    Archive reference number
    LBC
    Manuscript page number
    vol6 p424
    Material
    Dimensions
    height (page): 303mm
    width (page): 178mm
    Subject
    Description
    Diagram of a transverse scale.

    Johannes Hevelius’s Machina coelestis pars prior (Gdansk: S. Reiniger for J. Hevelius, 1673), included descriptions of the instruments Hevelius used for his astronomical observations. These included open-sighted astronomical instruments using transversal scales. Robert Hooke, in his Animadversions on the first part of the machine Coelestis (London: T.R. for John Martyn, 1674), criticised Hevelius for not using telescopic sights, given the limitations of human eyesight. In his letter dated 31 December 1673, John Wallis offered a mathematical justification for the use of transversal scales in this letter, thus siding with Hevelius in the subsequent dispute between Hooke and Hevelius about the appropriate instrument for accurate astronomical observations.

    This diagram is a copy of the one at LBO/6/353. It occurs in the original letter at EL/W2/16/002.
    Related fellows
    John Wallis (1650, British) , Mathematician
    Johannes Hevelius (1611 - 1687, German/Polish) , Astronomer
    Associated place
    <The World>
       > Europe
          > United Kingdom
    Powered by CollectionsIndex+/CollectionsOnline