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    Re: Slocum's lunars
    From: George Huxtable
    Date: 2003 Dec 18, 09:44 +0000

    A message from Cliff Sojourner read-
    
    >George Huxtable wrote:
    >
    >>Like Jan and Herbert, I found the story of the erroneous lunar table rather
    >>intriguing.
    >>
    >>In those days, tables for printing were set by hand, and there was much
    >>scope for things to go wrong. I have read of other cases of printed errors,
    >>and we can't reject the possibility of a whole column of them.
    >>
    >somehow I had the impression that there really was an error in the log
    >table.  intentional errors were not uncommon in mathematical tables,
    >sort of the same way map companies put fake streets on the maps, etc.
    
    =============
    
    Response from George-
    
    Yes, I suppose that intentional errors might have been introduced into
    tables, as with maps , though I haven't seen it documented. But surely, if
    that was being done, in order to detect copying, it would take place only
    in the least-significant digit. Rounding errors, when the predicted
    true-value is roughly half-way between two digits, might be tinkered with
    slightly to push the rounding up or down, by just one in the last digit, to
    a (marginally) unexpected value.
    
    That's the way I would put my "signature" on the numbers, anyway, without
    acting to the detriment of navigators. It would enable an illegal copy to
    be distinguished from a legitimate publication in which the predictions had
    been calculated anew.
    
    However, Slocum claimed that the erroneous table put his lunars hundreds of
    miles out. Surely no almanac would deliberately introduce such errors.
    
    George.
    
    
    ================================================================
    contact George Huxtable by email at george---.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    ================================================================
    
    
    

       
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