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    Re: NP303 VOL2 covers 0-49 degree declination? vs. PUB/HO 249 VOL2 0-29 deg dec?
    From: Gary LaPook
    Date: 2012 Aug 12, 10:22 -0700
    I always bring this up when people ask about selecting a sight reduction method. Try the Flat Bygrave slide rule that you can make yourself for about one buck that computes the data to the same level of accuracy as H.O. 249 and does the computation in less than two minutes, less than one minute when you get proficient. Go to my website at:

    To get compleet instructions on how to make and use one of these. Also look at:

    for a complete system which takes only five sheets of paper plus the two plastic sheets that comprise the Flat Bygrave itself.


    --- On Sun, 8/12/12, David Fish <davidafish@yahoo.com> wrote:

    From: David Fish <davidafish@yahoo.com>
    Subject: [NavList] NP303 VOL2 covers 0-49 degree declination? vs. PUB/HO 249 VOL2 0-29 deg dec?
    To: NavList@fer3.com
    Date: Sunday, August 12, 2012, 8:27 AM

    In searching around for various options for a set of H.O. 249, I came across the British Admiralty equivalent (I thought), but noticed that the cover indicates coverage in Volume 2 from 0-40 lat and 0-49 degrees declination... (NP303 Volume 3 cover indicates 39-89 lat and 0-29 dec in the same manner as H.O. 249 Vol 3).

    I've attached images of the respective covers for NP303 Vols 1 and 2 for your reference.

    Curious if anyone knows whether this is indeed a real difference or a misprint, and also what the logic might be for extended declination in the lower latitudes?
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