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    Re: Bygrave Scale Lengths
    From: Gary LaPook
    Date: 2013 Jan 30, 15:21 -0800
    That table mounted on the front of the MHR-2 is a simple time to angle conversion table.

    gl

    --- On Wed, 1/30/13, Brad Morris <bradley.r.morris---.com> wrote:

    From: Brad Morris <bradley.r.morris---.com>
    Subject: [NavList 22169] Re: Bygrave Scale Lengths
    To: garylapook---.net
    Date: Wednesday, January 30, 2013, 11:43 AM


    Hewitt

    There is an additional "Table".

    Perhaps that table does show "official instructions".  That would be fantastic!  The updated instruction then says

    "Use F-Table when declination is near zero and when the hour angle is near zero or 90 deg" 

    Or did I slaughter that too!?  :-?

    Image http://fer3.com/arc/img/122161.img_2161.jpg shows the first half of the Table.

    Image http://fer3.com/arc/img/122161.img_2162.jpg shows the second half.

    Can you make out what the title of the F-Table is?

    Oh yeah and... Thanks!

    Regards
    Brad

    On Jan 30, 2013 2:06 PM, "Hewitt Schlereth" <hhew36---com> wrote:

    Brad, it's been a long time since I did translations from German and I have never had hands on any cylindrical slide rule, in but the phrase,
    
    "Bei d nahe 0 oder t nahe 0 und 90  verwende F-Tafel",
    
    the verb "verwende" means 'use' or 'employ' an 'F-Table', which I would take to mean something ancillary to the main slide rule, like say a printed table.
    
    Hewitt
    
    
    
    Sent from my iPad
    
    On Jan 30, 2013, at 6:21 AM, "Brad Morris"  wrote:
    
    > Hi Gary
    > 
    > Image 122161.img_2160.jpg tells the tale!
    > 
    > In it, we see the rules for using the device.  Within those rules, we see
    > the standard admonishments for the MHR1, with one major and glaring
    > change.  In German, we have:
    > 
    > Bei d nahe 0 oder t nahe 0 und 90  verwende F-Tafel
    > 
    > Which I loosely translate to:
    > 
    > Do not use the slide rule (F-Tafel) when declination is near zero deg or
    > when the hour angle is near 0 or 90 deg.
    > 
    > The is no longer any numerical prohibition like 0 deg 20 min or 89 deg 40
    > min.  It just says "near" (nahe).  This could be understood to say the same
    > thing, since 20 min is near to zero.
    > 
    > But given the precise directions of the MHR1, I would like to think that
    > near now means that the scale has been extended downwards and upwards, as
    > we have discussed, towards 0 and 90 deg.  To what value?  The images do not
    > reveal this data point.  Pity.  I'd like to think that it went to within an
    > arc minute, the trick of a tiny offset to include 0 deg 90 deg not
    > withstanding.
    > 
    > What do you make of the conversion table, the adjustment knobs and the
    > magnifying glass?  Magnifiers are typically associated with verniers and
    > fine graduations.
    > 
    > Regards
    > Brad
    > On Jan 30, 2013 12:39 AM, "Gary LaPook"  wrote:
    > 
    >> ------------------------------
    >> 
    >> I am attaching some photos I took of the MHR2 in London in 2009.
    >> 
    >> gl
    >> 
    >> +++++++++
    >> 
    >> I would be very curious to see what the scale lengths and operating ranges
    >> of the MHR2 table top calculator. Ronald - Do you know these values?
    >> 
    >> ++++++
    >> ----------------------------------------------------------------
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    >> 
    >> Linked File: http://www.fer3.com/arc/imgx/f1-IMG_2170.JPG
    >> 
    >> *Attached File: 122161.img_2160.jpg
    >> *
    >> *Attached File: 122161.img_2161.jpg
    >> *
    >> *Attached File: 122161.img_2162.jpg
    >> *
    >> *Attached File: 122161.img_2164.jpg
    >> *
    >> *Attached File: 122161.img_2166.jpg
    >> *
    >> *Attached File: 122161.img_2167.jpg
    >> *
    >> *Attached File: 122161.img_2168.jpg
    >> *
    >> *Attached File: 122161.img_2169.jpg
    >> *
    >> 
    >> View and reply to this message: http://fer3.com/arc/m2.aspx?i=122161
    >> 
    > 
    > 
    > 
    > 
    > View and reply to this message: http://fer3.com/arc/m2.aspx?i=122166
    > 
    > 
    
    
    
    

    View and reply to this message: http://fer3.com/arc/m2.aspx?i=122168

    View and reply to this message: http://fer3.com/arc/m2.aspx?i=122169

       
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