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    Re: Lunars
    From: Fred Hebard
    Date: 2007 Sep 27, 12:46 -0400

    Newton apparently independently invented the double-reflecting
    instrument 20-30 years ahead of Godfrey & Hadley(?, not sure if the
    English guy was Hadley), and gave a secret presentation to the Royal
    about it.
    On Sep 26, 2007, at 1:11 AM, frankreed{at}HistoricalAtlas.net wrote:
    > I wrote:
    > "Consider: how would those folks who recommended the prize have
    > known back
    > in 1714 that there would be a device invented, twenty years in
    > their future,
    > that could reliably measure angles to about 1' of arc?"
    > And Fred, you replied:
    > "Newton would have made his secret presentation to the Royal about
    > then.  He
    > worked on the moon orbit problem."
    > Fred, I can't figure out what you're talking about here. The fact that
    > Newton worked on the 'moon orbit problem' has nothing to do with
    > the ability
    > to measure angles to some specified accuracy. As for his "secret
    > presentation" perhaps you should elaborate on what you think this
    > implies.
    > And I asked:
    > "Who in the world suggested that 1' of arc was the limit of
    > accuracy for
    > such measurements?"
    > You replied with one word, "Newton". I'm sorry, but I think you've
    > got two
    > separate lines of reasoning confused here. Newton was certainly
    > aware that a
    > certain level of accuracy in lunar distance observations and
    > predicted lunar
    > distances would be required to achieve a given level of accurcay in
    > longitude determination. But that's a trivial matter that anyone with
    > passing skill in astronomy could work out. He certainly didn't
    > offer any
    > predictions on the ultimate limits of angular measurements. Nor did
    > his
    > suggestions "set up" the lunar distance method as the intended
    > winner of the
    > Longitude Prize.
    >  -FER
    > >
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