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    Re: Brown-Nassau slide rule for clearing lunars
    From: Francis Upchurch
    Date: 2015 Oct 28, 01:48 -0700

    Thanks Frank,

    yes I fully understand the accuracy issues with lunars and made that point in my post, perhaps not very clearly. I am just interested in the BN and possible uses. I think a very big one may be accurate to say 1' ? we'll see.

    I generally get good results with the Fuller slide rule (usually same as calculator). Also, the hv-Doniol seems to work aswell. (see other post, which is stuck somewhere)

    I've tended to use the Karl formulae because I find them easier to understand than your series method, for a "visual" person like me with no natural feel for maths, the simple nav triangle pictures showing the vertical movements of the sun and moon alts (mostly with lunar parallax) can be seen directly in the formulae.

    i will however, take you sage advice and try the Fuller with the series method.

    Most of my lunars in the past, cleared with the Fuller by Karl formulae seem to be ok when checked against your web site calculator, which I always use as a final arbiter! 

    Many thanks again.


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