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Re: The Nautical Day
From: Trevor Kenchington
Date: 2004 Feb 6, 20:23 +0000
From: Trevor Kenchington
Date: 2004 Feb 6, 20:23 +0000
George, The Nautical Day, 24 hours early than the Astronomical Day, was long established and of general application -- at least in the English-speaking world. (Smyth, for example, treated it as an established fact, without reservations or caveats.) I'm not sure when it entirely ended. I have a vague memory that it was still used in the grain trade (under sail) in the 1930s, though I would be pushed to find a reference to that. My guess would be that mariners have been counting time noon-to-noon since Medieval times and that they named the day by the civil day on which they wrote up their log. Astronomers developed a different tradition. Once mariners needed almanacs, they just had to learn to allow for the difference in naming of the same day, until both changed to the civil day in the 20th century. I doubt that anyone really troubled over the extra complexity. It would have been one of those things that a trained professional would do without needing to think and yet would make the craft of navigation a closed book to amateur pretenders -- a distinguishing mark that the initiates would be very reluctant to give up. Trevor Kenchington You wrote: > I had dismissed the Nautical Day as something of an early American > aberration, but Scoresby has shown me that view was wrong. > > So why on Earth would mariners use yet another timescale, differing from > both civil time and astronomical time? Were some almanacs, perhaps, printed > with Nautical Time as their argument? How prevalent was this use of > Nautical Time, how far back did it go, when in practice did it end? Was it > common within the whaling community generally? -- Trevor J. Kenchington PhD Gadus@iStar.ca Gadus Associates, Office(902) 889-9250 R.R.#1, Musquodoboit Harbour, Fax (902) 889-9251 Nova Scotia B0J 2L0, CANADA Home (902) 889-3555 Science Serving the Fisheries http://home.istar.ca/~gadus