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    Re: Calculator v. Slide Rule for Ex-Meridian Correction
    From: Francis Upchurch
    Date: 2016 Jan 3, 22:19 -0800

    Thanks Frank. 

    Yes, I did read most of your earlier posts and explanations on the series method, but hadn't understood why 3 place accuracy was acceptable. I assume, for the  cosine method for either Hc sight reduction of "Karl" type lunar clearance, then 4+ places and therefore a calculator or a cylindrical slide rule are still  required?

    I guess my celnav hobby is an obsession and yes, like many others that "compells" us to use obsolete technology like sextants, pencils and paper and in my severe form  of the illness, slide rules! ( I always check results with calculator or your online lunars when within range.). But for me it is just fun.

    You may be pleased (or not!) but hopefully amused to hear that I have recently developed yet another compulsion, partly curtesy you. I have printed off the beautiful Margett book of "tables" from the PDF you kindly supplied.I am now binding it in an A3 book type folder and hope to test drive it with a few lunars soon. All this of coarse is completely unnecessary and obsolete with my quartz watch, smart phone, GPS etc.

    Good soul food and fun though!


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