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    Re: Haversines with Logarithms
    From: Matthew Gianelloni
    Date: 2020 Oct 16, 04:10 -0700

    Brian Walton wrote:

    I currently have charge of a 68’ traditional motor vessel. I have in hand, a copy of Inman’s Nautical Tables, 1947 version, first published in 1821. My copy contains a reviser’s preface which describes a revision made by Rev Hall, in 1910. This revision note, also contained in my copy, gives the all-haversine formulae for solving spherical triangles, and layout and examples of their use.

    My copy contains combined tables for natural and log haversines, which deliver the answer in Right Ascension, for those using almanacs in that form.

    Brian,

    Wow. I will try to get a copy of that. What most interests me now is how they would annotate the conversation to right ascension, since I have only been able to get a mathematical result with a Meridian Angle. I have to either add it to the GHA of the target if the target is west of my position at sighting, or subtract from 360° if it is East to get Longitude. Is the R.A. solution similar?

    Matt

       
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