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    Re: Star-star distances for arc error
    From: Brad Morris
    Date: 2009 Jun 29, 05:20 -0400

    Hi Doug
    you wrote:
    Bygrave slide rule:
    It was my prompting of Peter Martinez to post about the Bygrave slide rule, as 
    I asked him to help produce a better computer derived scale.  We are of the 
    opinion that although there is room for discussion and both systems can be 
    considered alongside of each other as they reach the same result,  that isd:  
    of logCotan/ logCos scales,  or,   logTan/ logCosecant;
    I am completely convinced Bygrave made an error in his patent description 
    referring to log Cos scale, and that the scales are definitely logTan  and 
    logCosecant.  I do not want to rehearse the arguments here. It is immaterial 
    which you choose;  but what struck me was the unwillingness of some here to 
    even consider this alternative argument.
    My response:
    In my recent postings with the Visual Bygrave, you will find I give equal 
    credence to the Secant/Tangent pair and the Cosine/CoTangent scales, and have 
    so since this discussion began.  The point is proven, it can be either.  I 
    agree hole heartedly, Bygrave did not present this information in his patent. 
     Either scale pairing provides the correct answer.  This is to be expected, 
    as Secant is the inverse of Cosine, while Tangent is the inverse of 
    Cotangent.  While others may continue to doubt your proposition, I think it 
    quite reasonable.  Don't let the peanut gallery get you down!
    Best Regards
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