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    Re: Working a lunar
    From: George Huxtable
    Date: 2007 Sep 21, 10:59 +0100

    I've been asking Henry Halboth where his lunar distance tables, to be used
    as he suggests for emergency navigation, were to come from, and he tells us-
    "As respects tables of Lunar Distances, I have been using beautifully posted
    tables at http://www.math.uu.nl/people/wepster/tables.html which have been
    well put together and can be printed off for a number of years, as well as
    for any particular voyage time frame."
    Good for him. I think that preprinting those tables, to cover an intended
    voyage, would indeed fulfil his intended purpose, being just like the tables
    in the old almanacs.
    I wonder if he recognises their author, as Steven Wepster, about whom I
    wrote in Navlist posting 3216, just three days ago. He will be receiving his
    doctorate for his lunar researches in Utrecht on Tuesday, as long as he
    succeeds in defending his thesis against an examination in public.
    Henry added-
    " I see little use to the so called approximate methods of clearing the
    distance. I find a pure trigonometrical solution, espescially by use of the
    haversine formula, to be more understandable and certainly with fewer
    corrections - I have yet to test the difference in accuracy as between
    5-place and 6-place logarithms and have not been able to locate any 6-place
    natural haversine tables. "
    I would welcome more detail from Henry about his use of that method.
    I presume that his recent spot-on lunar was taken from on land. Is that
    correct? Could he then see a good horizon, beneath the azimuth of each of
    the two bodies, for taking the altitudes? How much does he think his lunar
    distances might be degraded, if they are taken from a smallish boat, such as
    a sailboat or a lifeboat, in a moderate sea?
    contact George Huxtable at george---.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
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