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    Re: Eclipse Island's 1766 Eclipse Observation
    From: Peter Blaskett
    Date: 2024 Apr 14, 21:31 -0700

    Jim Wyse, et al

    I have located a method of finding the longitude using a solar
    eclipse described by "Kerigan" in 'The Complete Mathematical
    and General Navigation Tables'. Available here:


    https://www.google.com.au/books/edition/The_Complete_Mathematical
    _and_General_Na/l5IAAAAAMAAJ?hl=en&gbpv=1&dq=kerigan+longitude
    +by+solar+eclipse&pg=PA531&printsec=frontcover

    A fully worked example is given, beginning page 557, Problem XVI.

    Using "EclipseWise.com" by Fred Espenak, the modern values of the
    example are shown in file1.


    Using Stellarium at 16:32:04, a Local Apparent Time of 4:23:18
    is found.

    EOT is 3m 57s So Local Mean Time is 4:19:21

    Assumed diff long of 3d 11’ = 0:12:44 of time

    Applied to LMT gives a UT of observation 16:32:05
    Note: they still reckoned time from noon

    This looks well with the modern value of 16:32:15

    Kerigan’s calculation is laid out in file2 :

    I have not yet begun to try and replicate this computation.

    Also, I doubt that this is a method which would have been used by
    Witchell to compute Cook's data. I'm confident he used something
    other, but I haven't found it yet.

    It's all a hunt in progress.

    File:


    File:


       
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