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    Re: The repeating reflecting circle.
    From: Alexandre Eremenko
    Date: 2005 Jan 16, 23:45 -0500

    On Sun, 16 Jan 2005, George Huxtable wrote:
    > Looking at Fred Simms' other publications,
    > he is clearly a mining engineer,
    He says on the title page of the book that he is:
    "Surveyor and Civil Enineer,
    Late of Royal Observatory, Greenwich, and
    formerly employed on the Ordnance Survey".
    > and maybe his instruments have a mining connection.
    > In which case, perhaps
    > it's possible that to him, a dipmeter might be a device
    > for measuring the
    > dip of an underground seam,
    > rather than a device to measure the anhedral
    > angle between two opposite horizons. Just a thought.
    This is not the case.
    I site the history of the dipmeter from Simms book:
    "When the late professor Vince was engaged in making
    observations upon extraordinary refraction in Ramsgate,
    Mr Throughton contrived and constructed for his
    use an instrument which he
    called a Refraction-Sector.
    About five years afterwards, when preparations were making for
    the first of the late North Polar Expeditions,
    Mr Troughton was applied to by the late Dr Wollaston,
    to make him an instrument on the principle of back observation
    with the quadrant, to send with the expedition, to measure
    the dip of the horizon; but upon Mr Troughton's producing his
    Refraction-Sector, which was as well adapted to Dr. Wollaston's
    purpose as that for which it was devised,
    the Doctor immediately ordered
    one to be made for him, and named it a Dip-Sector.....

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