NavList:

   

Reply

I've recently been reading "The Arctic Whaling Journals of William Scoresby
the Younger, vol 1." ed. C. Ian Jackson, pub. The Hakluyt Society 2003.
This covers his first three voyages as master, in 1811, 1812, and 1813.
Scoresby made 12 such voyages, and it is intended that future volumes will
cover the rest.

Scoresby was involved in the "Greenland Whaling", which took place each
year to the East of Greenland, near to the Western coast of Spitzbergen.

While in port, and when making his way out to sea, Scoresby's journal was
written up according to the calendar day, as we're all familiar with,
starting at ending at midnight.

Most of us are aware that until the 1920s, time in the Nautical Almanac was
in terms of the Astronomical Day, which started at the noon of the calendar
day having the same date. The Astronomical Day was therefore 12 hours after
the corresponding calendar day.

However, as soon as Scoresby had got to sea, he started to write his
journal (which was effectively his log) according to a different timescale
altogether, the Nautical Day. This started and ended at the noon PRECEDING
the calendar day with the same date.

I had heard of the Nautical Day before, but the only reference to it I have
been able to find is in Bowditch vol 2 (1981) in which he says-

"Nautical Day- Until January 1, 1925, a day that began at noon, 12  hours
earlier than the calendar day, or 24 hours earlier than the astronomical
day of the same date."

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?

In the 18th century voyages of exploration I have read, I don't remember
seeing any references to Nautical Time at all. So it doesn't seem to have
been part of the exploring navigator's baggage, in the half-century
preceding Scoresby.

Can anyone offer any light on this matter, or provide any references that
mention it?

George.

================================================================
contact George Huxtable by email at george@huxtable.u-net.com, by phone at
01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
================================================================

   

Reply