Detail of dial. Made by Samuel Watson (1635-1710), London, this is the earliest English astronomical clock in which the sun is fixed, according to the Copernican principle (expounded in 1543). Besides the time of day, it shows the date, position of the sun in the Zodiac, phases of the moon and its latitude (important for eclipse predictions) and the times of sunrise, moonrise and moonset. The time of hightide at London Bridge can also be read off. Samuel Watson was born in Coventry in about 1635 and worked there until about 1690, when he moved his busines to London.
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