A rare W & S Jones Cometarium,  English, early 19th century,
Lot 137
A rare W & S Jones Cometarium, English, early 19th century,
Sold for £39,650 (US$ 66,644) inc. premium
Lot Details
A rare W & S Jones Cometarium, English, early 19th century,
signed W & S Jones, 30 Holborn, LONDON the mahogany case containing the hand cracked geared mechanism, mounted on top with a brass model of Sun and comet marker traversing an elliptical tract, the pointer mounted below the Sun moves over the radial divisions of the outer brass scale as the pointer (replaced) moves over the small circular dial showing the time and divided in to 30 degrees divisions or signs, replaced handle at the side, the case, scale 12 by 10 by 7in (30.5 by 25 by 18cm)

Footnotes

  • A cometarium is a mechanical device designed to illustrate the motion of a comet about the Sun. The key feature of the instrument is the ability to show an apparent increase in orbital velocity as the comet marker moves from aphelion (the point in an elliptical orbit that is at the greatest distance from the Sun) to perihelion (the point in an elliptical orbit that is closest to the Sun). This demonstrates Kepler's second law of planetary motion.

    The model that ultimately became known as the cometarium was first made by J T Desaguliers in the early 1730s. He used his model, which described the orbit of the planet Mercury, to the assembled Fellows of the Royal Society on the 8th March 1732.

    Benjamin Martin first used the term cometarium in the early 1740s and in the mid 1750s James Ferguson used the expression equal-area machine for the device.

    The only other cometarium by W & S Jones know to be extant is in the Science Museum, London.

Activities
Contacts
  1. Jon Baddeley
    Specialist - Scientific Instruments
    Bonhams
    Work
    Montpelier Street
    London, SW7 1HH
    United Kingdom
    Work 0207 393 3872
    FaxFax: +44 20 7393 3873