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    Re: Poor St. Hilaire
    From: Geoffrey Butt
    Date: 2007 Nov 3, 13:51 -0000

    George
    
    I believe you have put your finger on precisely why there is misuse and
    misunderstanding of the term 'Assumed' Position:  and clarified for me why
    some of my students don't instantly latch on to what I am saying to them
    about sight reduction.
    
    The original meaning of the word 'to assume' meant to take up a position or
    office;  "he assumed the position of first mate".  Only later did 'to
    assume' acquire the meaning in popular usage of making use of a convenient
    value or fact.
    
    For some reason (probably due to receiving an 'old-fashioned' education from
    literate teachers) I have always understood 'Assumed Position' to mean what
    would have been the understanding when inspection tables were first produced
    (eg Revd Ball, 1907) - namely, that one imagined physically relocating to
    the AP and used the tables to find what would be seen from that position.
    
    'Assumed' means 'going to a location' not 'taking up a convenient value'.
    
    Geoff Butt
    
    ----- Part of Original Message -----
    From: "George Huxtable"
    :
    : And (reluctantly) he accepts the name Assumed Position, or AP to refer to
    : "any preselected point defining the region of interest", quibbling
    somewhat
    : about that name by saying "... that's misleading; we are not assuming the
    : ship is there- on the contrary, we usually expect that it is not". But (to
    : quibble back) isn't that what the word "assuming" implies? You "assume"
    : something to be the case, whether or not it actually IS the case. Usually,
    : "assumed position" has been used for a position which is deliberately
    : displaced from the DR, to allow whole-degree entries in the alt-az tables
    : (and an unnecessary distraction when using a calculator, as John Karl
    : recommends). Later in the book, he uses AP in that special context.
    :
    : What I'm saying, really, that his use of DR, AP, EP can be different from
    : the usage you may find elsewhere, which is fair enough, when those
    meanings
    : have been carefully defined. Indeed, you may find in other works the terms
    : chosen position, trial position, just to add to the complicated mix.
    :
    : George.
    :
    
    
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