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    Re: A Lunar from the 1840s
    From: Frank Reed CT
    Date: 2004 Dec 5, 15:34 EST
    I pointed out a page in an old logbook wth a lunar calculation from the 1840s. It makes an interesting puzzle but it's hard to read, and I know some of you don't like following links. So here's a transciption of the calculation. Words in brackets are mine. Everything else is straight out of the logbook. I have added leading zeroes to many of the angles and logs so that they will format correctly (at least I think they will).
     
    Here's the Puzzle:
    See if you can figure out the vessel's position from the information here. Most of it makes sense, but there are a few little oddities in the calculation... First things first, you need to figure out the year. That means you'll need to find a geocentric lunar distance among the numbers below and then compare it with a modern calculation (e.g. from HistoricalAtlas.com/lunars). You'll also want to figure out what's gong on in each of the eleven sections of the calculation. For an example, section 4 is a calculation of the Moon's (augmented) semi-diameter. What method is being used to clear the lunar?
     
    [BEGIN]
    Distance from the Sun and Moon taken
    February 9th at 5P.M. in Long 140..00W Long [sic] Bound
    around Cape Horn
    ----------------------------------------------------
    [Section 1: top middle]
    Sun
    24..57
    00..12
    ---------
    25..09
     
    [Section 2: immediately to the right of above]
    10..24
    00..20
    ---------
    10..04
     

    [Section 3: at right top]
    Chronometer
    01..19..00
    00..50..30
    --------------
    02..09..30
     
    [Section 4: at right middle]
    15..17  [labeled "8th"]
    15..23  [labeled "9th"]
    ---------
    00..06
    ---------
    00..01
    ---------
    15..18
    00..03
    ---------
    15..21
     
    [Section 5: immediately to the right of above]
    56..05  [labeled "8th"]
    56..30  [labeled "9th"]
    ---------
    00..25
    ---------
    00..06
    ---------
    56..11
     
    [Section 6: left column]
    105..57..45   [could be 51 or 52 or 57]
    000..02..45
    ----------------
    105..55..00
    000..13..08   [??]
    000..15..21   [carried over from right]
    ----------------
    106..23..29
    000..03..14
    ----------------
    106..26..43
    000..27..48   [from log calculation below]
    ----------------
    105..58..55
    104..56..18 
    ----------------
    001..02..37
     
    [Section 7: middle: 1st column of logs]
    00.5057
    10.3716
    09.9818
    -----------
    00.8591
     
    [Section 8: immediately to the right of above. 2nd column of logs]
    00.5057
    10.7574
    10.5297
    -----------
    01.7928
     
    [Section 9: just below 2nd column of logs]
    24..54
    02..54
    ----------
    27..48
     
    [Section 10: aligned with lower right of left column]
    4586 [proportional logs]
    3143
    ---------
    1443
     
    [Section 11: at bottom, aligned with "1443"]
    02..09..07  [GMT]
    12
    --------------
    14..09..07
    14..09..30
    --------------
    23 [seconds]
     
    [END]
     
    Frank R
    [ ] Mystic, Connecticut
    [X] Chicago, Illinois
       
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