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    Re: Bowditch Table 9
    From: Herbert Prinz
    Date: 2002 Apr 11, 17:49 +0000

    Hello Martin,
    
    Welcome to the list.
    
    
    > "Angle" runs from -4 minutes (a puzzle in itself) to +30 degrees;
    >
    
    That's the easy one. The angle has to be corrected for dip by which it can
    become negative.
    
    >
    > The formula given in my 1981 Bowditch is
    >
    > Distance = sqrt (
    >        ((tan A)/0.0002419)**2
    >    +  (H-h)/0.7349
    >     -  (tan A)/0.002419
    > )
    >
    
    I can't answer this. Obviously, the formula is severely garbled. Ignoring dip
    and refraction completely, but using some common sense, we have d = (H-h) / tan
    A, or if you like this better, d = (H-h) * cot A.  How one gets from here to
    what Bowditch has by applying correction for refraction is totally beyond me.
    
    Keep up the good work. 8000 more and you will beat Bowditch. (He claimed to
    have found that many errors in Moore.)
    
    Best regards
    
    Herbert Prinz
    
    
    

       
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