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    Re: Lunar era
    From: Henry Halboth
    Date: 2004 Dec 7, 10:12 -0500

    My experience at sea with Lunars generally indicated an accuracy between
    15 and 30 minutes of Longitude. However, when I was experimenting it was
    necessary to do all calculations "by hand", including actual distances
    once published in the NA and now rather prolific on the Internet - it's
    rather hard to say at this date how many errors may have inadvertently
    crept into my work - I was a lot younger at that time and not quite so
    patient as I now sometimes am.
    You have expressed some mathematical interest in the "by hands"
    calculation, and I would note this to be somewhat simplified by use of
    the haversine formula, as opposed to the longer format originally
    employed. Some time ago, I posted a work format for this method, compared
    with actual problems published in Norie's utilizing Borda's method, and
    showed a difference of some three (3) seconds in the cleared distance - I
    tried posting this format on the List, however, the prohibition with
    respect to attachments really screwed up the presentation. I would be
    pleased to separately forward you a copy of this format and would welcome
    your comments mathematically.
    On Mon, 6 Dec 2004 14:10:48 -0500 Alexandre Eremenko
    > The question of lunars accuracy in practice
    > was apparently touched many times in this list.
    > But I could not find much of the row experimental data.
    > So I ask those who really practice lunars in sea
    > or on land: can you give some statistics of the accuracy
    > of your own distance measurements?
    > Alex.

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