Calendar watch
Watchmaker: Thomas Alcock
The concentric chapter rings of this unusual dial indicate the time of tides (presumably at London Bridge), mean solar time (I.XII), the age of the moon in its monthly cycle (1.291.2), and the day of the month (1.31). The moon's phases can be read though the circular aperture in the center disk. The February 1661 issue of Kingdoms Intelligencer, a newspaper published by the English parliament in opposition to the king, reported the loss of a comparable watch by Alcock.
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