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    Re: Sight Reduction Formula Question
    From: Trevor Kenchington
    Date: 2005 Jan 9, 15:21 -0400

    Thank you.
    You wrote:
    > My 2-volume edition of Bowditch (vol.2 is 1981) states and derives all
    > three expressions. In vol 2 it's in "part 3, Navigational calculations", in
    > chapter 7, "Calculations of Celestial Navigation", paras 707-710.
    My Bowditch is the 1995 edition and the nearest comparable material that
    I can find is in para 2205. That gives the cosine and tangent
    expressions (not the sine) but does not explain the derivation of either
    of them. (Nor does it show how the formula for altitude is derived.)
    Maybe my 1955 edition of the Admiralty Manual of Navigation (Vol.III)
    will explain it all -- when I can make time to slowly work through that
    and the two preceding volumes.
    Trevor Kenchington
    Trevor J. Kenchington PhD                         Gadus@iStar.ca
    Gadus Associates,                                 Office(902) 889-9250
    R.R.#1, Musquodoboit Harbour,                     Fax   (902) 889-9251
    Nova Scotia  B0J 2L0, CANADA                      Home  (902) 889-3555
                         Science Serving the Fisheries

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