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    Time at Sea in 1703
    From: Chuck Taylor
    Date: 2004 Nov 3, 19:08 -0800

    I recently purchased a copy of "Marine Navigation
    Instruments" by Jean Randier.  It was originally
    written in French in about 1977(?) and was translated
    into English in 1980. It is profusely illustrated with
    a wealth of wonderful photos, but what I am writing
    about is an anecdote I found in it about timekeeping
    at sea in the days before chronometers.  Note that
    this was before the days of time zones, and ships were
    operated on local (solar) time.  I hope that some of
    you may find it as enjoyable as I did.
    
    "Sand glasses ... are very early instruments for
    measuring the elapsed time and were to be found on
    board ship from the time of the first great maritime
    expeditions. ... The very fine sand with which
    sandglasses were filled was generally finely crushed
    eggshell, or, according to the ancient chronicles,
    black powdered marble 'baked nine times'.  On board
    ship the half-hour glass was turned on the dot of noon
    and then at each half hour until the next day.  It
    soon became common to strike the watch bell whenever
    the glass was turned, which explains the old
    sailing-ship custom of giving a double stroke for the
    full hours and four double strokes at midnight, four
    o'clock, eight, midday and so on to signify the number
    of times the glass had been turned.
    
    "Accuracy was entirely relative, as will be seen from
    the account of the fleet of Duguay Trouin, which was
    caught in a thick fog off Spitzbergen in 1703:  'Fog
    is such a frequent occurrence in these parts that it
    led us into a most strange error.  Aboard our ships
    half-hour sand-glasses are used that the helmsmen are
    required to turn eight times to measure each watch,
    which lasts four hours, at the end of which time the
    watch is relieved.  It is fairly common, however, for
    the helmsmen to turn the glass before all the sand has
    run through in order to shorten their watch a little.
    This is called 'swallowing the sand'.  This error, or
    rather misconduct, can be corrected only by taking the
    altitude of the sun; however, as we were without sight
    of the sun for nine consecutive days because of
    continuous fog and as in that season and latitude the
    sun only circles the horizon, making the days and
    nights equally bright, in the course of eight days the
    helmsmen managed, by dint of swallowing the sand, to
    turn day into night and night into day so that all the
    vessels of the squadron without exception found an
    error of at least ten or eleven hours when the sun
    reappeared.  This had so upset the times of eating and
    sleeping that we all generally wanted to eat when it
    was time to sleep and sleep when it was time to eat.
    However, we did not take any notice of this until we
    discovered the truth by taking the altitude.'"
    
    --
    Chuck Taylor
     48d 55' N
    122d 11' W
    
    
    
    
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