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    Re: Celestial Navigation at NEAF
    From: Lu Abel
    Date: 2015 Apr 18, 22:05 +0000
    It could be that the mediocre sight accuracy is due to the fact that the artificial horizon is not dead level. 

    What was supporting the mirror?  Is there a way of checking/adjusting its levelness? 

    It doesn't take much -- just a minute or two of being off-level.

    From: Bruce J. Pennino <NoReply_Pennino@fer3.com>
    To: luabel@ymail.com
    Sent: Saturday, April 18, 2015 2:46 PM
    Subject: [NavList] Re: Celestial Navigation at NEAF

    The mirror floating in pool is really elegant. I’m jealous. I now regret all of my effort to use a steel plate with leveling screws, plus all of the other refinements I built into my “system” so I could use it on steep uneven ground etc.
    Simple is best. Accuracy of plus/minus 1 mile is probably  happenstance good fortune. With a quality sextant I would believe  plus/minus 1.5-2 miles.  What is typical best  accuracy with mirror or pool of fluid?


    Sent: Saturday, April 18, 2015 4:01 PM
    Subject: [NavList] Celestial Navigation at NEAF
    I visited the North Eastern Astronomy Forum (NEAF) at the SUNY Rockland Community College in Suffern, New York. Amongst the gathering of solar telescopes I found Gary the Astronomer offering free sextant lessons to anyone who would listen. Kudos to Gary.
    He was using a Davis plastic sextant and for an artificial horizon had a sheet of glass in a wooden frame floating in a pan of water (see the attached photograph). He claimed to be able to get 1 mile accuracy.
    Robin Stuart

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