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    Re: timepiece history - when did second accuracy become feasible
    From: George Huxtable
    Date: 2007 Nov 1, 23:32 -0000

    I wish to question just a bit of Mike Daly's useful posting, in which he
    | Hours come from the Romans - they tended toward a duodecimal system and
    | used 12 hours to divide the day.  These were unequal in length.
    | Eventually, 12 were applied to night as well and they became equal in
    | length.
    I'm not sure he has that unequal-hours business right. As I understand it,
    the unequal-hours system divided the daylight hours, between dawn to dusk,
    of the working day into 12 EQUAL hours, and it divided the night hours,
    between dusk and dawn, also into 12 EQUAL hours, but the day-hours were
    unequal to the night-hours. In the Summer, the day hours would be longer
    than the night hours; in Winter, vice versa. In Mediterreanean latitudes,
    those differences were not so great as in our more Northern latitudes, here
    in Britain. The higher the latitude you get to, the more unwieldy that
    division method becomes.
    So, when (for example) monks had set times for singing certain psalms, or
    whatever it is that monks do, some would always be in daytime, others always
    in the dark, and that wouldn't alter between Summer and Winter. That's a
    system that continued right up to the adoption of clockwork to ring the
    bells, in the middle ages.
    Mike recommends Landes' book "Revolution in Time", and I agree, but with
    some reservations. It's written in beautiful and imaginative English, it
    makes many perceptive points, but oh, doesn't it philosophise and wander,
    often at great discursive length! I would be searching for a bit of hard
    technical information, about how the things worked, and it's there to be
    found, but not until you get to the appendix.
    contact George Huxtable at george@huxtable.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
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