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    Bris sext. was: Re: John Rae
    From: Alexandre Eremenko
    Date: 2005 Oct 30, 14:48 -0500

    Dear John,
    I am glad that there is a feedback on my postings
    on the Bris sextant.
    So I continue, simultaneously answering your questions.
    Here are my (genuine, Bris-made, CP-sold) Bris angles.
    There are 8 "Suns", not counting the real one.
    3 bright, 4 dim, and one (No 8) very dim.
    Row data from calibration observation on Jul 28, 2005,
    Nx refers to the
    Sun number x
    from above, UL and LL are upper and lower limbs true altitudes. The
    numbers are true
    angles for given time and place, NOT corrected for refraction
    and dip. Time and place were
    determined by the on-board GPS. The elevation was
    approx 6 feet, and the waves were substantial.
            LL        UL         DIFFERENCE
    N1: 10d04.5'  10d37.3'            32.8
    N2: 12d29.5'  13d03.0'            33.5
    N3: 20d39.1'  21d07.1'            28
    N4: missed    23d33.3'
    N5: 25d31.8'  25d58.9'            27.1
    N6: 33d30.5'  34d00.2'            29.7
    N7: missed    35d55.8'
    N8: 45d53.2'  46d22.2'            29
    The true Sun diameter was 31.6, according to Almanach.
    P.S. I have ONE more observation July 30 (of some limbs of some Suns)
    to compare but I never reduced it. The problems were that
    a) the sunny days/times were rare (North sea), and
    b) I had to stand my watches at the rudder, and
    c) I had to peel potato for the dinner, etc:-)
    e) When the good weather was in my free time, I did ordinary sextant
       observations with my SNO-T.

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