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    Admiralty Manual of Navigation Vol III
    From: Michael Bradley
    Date: 2017 Apr 7, 13:06 -0700

    A small advertisement follows:

    It's possible to get the impression that James Wilson with his 1985 paper and its references was the original source for the formula to find the time difference between maximum altitude and true local noon, which has recently caused a flurry of interest.

    The whole thing, two different derivations leading to the same formula, plus a useful table of of 15.28 x Tan (dec or lat ) can be found in Vol III of Admiralty Navigation Manual 1938 (47 years earlier ) in Chapter XII 'Rates of change in Azimuth and Altitude'.

    It's a grand book to look out for if you can find a copy. Repeatedly bits and pieces of Navlist discussions are more than adequately covered therein. For example Aquino, Yonemura, Ageton, Ogura, Dreisenstock, Pierce, Blackburn, are all explained in Chapter X. Chapter XX is a treatise on finding and correcting chronometer errors, including the use of equal altitudes....

    Good navigating

    Michael Bradley

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