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    Re: Persistence and demise of Lunars
    From: Robin Stuart
    Date: 2017 Dec 6, 06:48 -0800


             I expected you’d have something like this. Thanks for posting it again. One thing you might want to include is a mention of Mr. Woolhouse’s appendix to the British NA of 1836 dealing with eclipses and occultations and which seems to have been the standard reference on the subject.

             Presumably the availability of chronometers that kept time adequately over the typical timescales that mariners were out of sight of known landmarks is what doomed lunars. However looking into the logs of the Shackleton expedition of 1914 makes clear the tremendous effort that went into the care and feeding of the chronometers. While Endurance was trapped in the ice they were constantly timing occultations (the rich cousins of lunars), sometimes several in a single night, to rate their chronometers and determine longitude.  Tables of occultations (and “Moon Culminating Stars”) outlasted Lunar Distance tables. Do you happen to know when they were eliminated and what actually caused them to be no longer relevant…radio time signals…end of multi-year expeditions…?



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