Augsburg clock, c 1630.
© Science Museum / Science & Society Picture Library
Clocks of this type were being made in Innsbruck, Vienna, and in Augsburg and other parts of Germany during the late 16th and early 17th centuries. This clock shows mean solar and lunar time. The phase of the moon is shown by the circular opening in the disc carrying the moon-pointers, while the moon's age can be read from the position of the edge of the moon-pointer on the circular scale on the disc carrying the sun-pointer. The remainder of the main dial is an astrolabe and shows the position of the sun, moon and a number of selected stars in the heavens. The lower left-hand dial gives the Dominical Letter (or letters) for the year, and the number of the year in the solar cycle. The dial on the right side of the clock shows which quarter has chimed.