At 10:20 PM 10/1/2001 +0000, Krzysztof Kotynia wrote:
>Since 1930 and the decision of the International Astronomical Union
>the EoT has been treated as an instrumental correction
>(EoT = AT - MT). It should been added to a mean time to receive
>a true time, like every instrumental correction should be added
>to the measured value to receive the corrected value.
>
>`Unfortunately' sundials give at once a true value.
Actually, this viewpoint is much older than 1930. I have a
set of English almanacs from 1714. The first one, titled
"The Ladies Diary: or, the Woman's Almanack," has the
following entries for the last month of that year:
Dec. 1 Watches and Clocks 5 min. 49 seconds slower than the Sun.
Dec. 5 Watches 4 min. too slow.
Dec. 13 Now again do all good Clocks, Watc. and Sun-dials go alike.
Dec. 15 Now Clocks are got 1 minute before the Sun.
Dec. 23 Watches too fast 5 min.
So, in earlier centuries even good clocks were considered
to give the *wrong* time except on four dates of each year.
-- Roger
