"Equation" refers to a difference or correction, as Fer J. de  Vries
has pointed out.

"a quantity added or subtracted in equating a computation" -
Webster's Third International Dictionary

Probably the first table of corrections for regulating a clock was
the "Tabula Aequationis Dierum" compiled by Christiaan Huygens
circa 1662.  Tables were published by John Flamsteed in 1666 and
John Smith in 1688. "A Table of the Equation of Days shewing How
much a good Pendulum Watch ought to be faster or slower than
a true Sun-Dial, every Day in the Year" was printed as early as 1683
for Thomas Tompion.  - from "The Grandfather Clock" by Earnest
Edwardes.

Gordon Uber


At 08:37 97/10/13 +0100, you wrote:
>I know WHAT the equation of time is.
>What I would like to know is - WHY is it called that?
>Isn't an equation supposed to contain an equals (=) sign?
>Surely it is really a correction factor?
>Should it not go something like:
>Local Mean Time = Local Apparent Time + Correction
>Anyone know anything about it?
>Like WHO named it and WHEN?

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