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    Re: Impossible lunar example. was: Short-cut lunars. was: Clearing lunars
    From: Antoine Couëtte
    Date: 2010 Aug 29, 01:42 -0700

    Dear George,

    In reply to your lehghty reply about trying to reckon the time of the "impossible lunar" into our current UT / Date times cale:

    - First of all, thank you very much for your very detailed insights,

    - I had come to the conclusion that at @6:10 p.m. in late november, there is no way for the Sun to be seen at a height of some 17° anywhere on the Greenwhich W009° Meridian.

    - So, and by respect to Sir Maskelyne, I am making the assumption that there is a "one figure typo" (and just one figure) in our quoted example, with the typo error originating not from Maskelyne himslef, but from somebody else.

    There could be a typo in :

    - the date of the month, not the month itself since it is in full letters, or

    - one of the quoted heights (probably in the leftmost digit, i.e. the one multiple of 10), or

    - the quoted Longitude, or

    - the quoted Distance (some doubt here), or

    - the quoted year.

    This is a fairly lenghty list, but it can be worked out.

    From what I can read, this Lunar took place on November 20, 1796 at 6h10 PM from a place located on the Greenwhich W009° meridian.

    So, my question is twofold - and anybody else, please feel free to reply - :

    - do the numbers I read look the same to you ? I am not sure since you quoted a date ot Nov 10th, while I can read Nov 20 th, and

    - as regards the time of 6:10 PM read on the W009° meridian, and given it is a "local time", it shows as 6:46 PM Greenwhich Time - which makes sense - (see one of your documents).

    So, I just need to know whether this time/date of Nov 20, 1796 , 06:46 PM Greenwhich (true) time would translate to-day into Nov 20, 1796 with a UT value approximately equal to "18:46 + Equation of Time".

    As long as I can have an approximate UT time to +/- 30 minutes as reckoned by to-day standards( and I do NOT think it is necessary to add/substract again any extra 12 hour value) and as long as I know that the actual date would be Nov 20, 1796 by to-day reckoning standards (no need to add substract one day, no ? ), I am happy.

    So I just need confirmation that the date and hour I read and I am reckoning into our current time scale system are not subject to any gross and systematic error.

    (not easy somtimes to make one self clear to others ...)

    Thank you and

    Best Regards


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