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    Re: Time sight primer
    From: David C
    Date: 2019 Sep 27, 15:52 -0700

    It is an over simplification to state that there was a time sight method and a Marc St Hilaire method. There were many methods proposed by the Extra Masters and other experts.  How many of the methods were actually used is another matter. I have attached the contents page from Blackburne's  "Tables of Calculated  Hour-Angles". Note the various ways of using the tables

    It is possible that these methods were dreamed up by Blackburne sitting in his armchair, smoking his pipe and dreaming up ways of increasing sales of hs books. On the other hand maybe some navigators did use them.

    Note that there were methods that involved plotting LOPS and others that did not. Some versions of the intercept method and long by chron dd not require plotting.

    All this changed (and IMHO became boring) with the introduction of the HP35.


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