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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: timepiece history - when did second accuracy become feasible
From: George Huxtable
Date: 2007 Nov 1, 23:32 -0000
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 wrote-. | 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. George. 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. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---