The pendulum clock

Type:

Book Chapter

Author:

Gregory L Baker; James A Blackburn

Published:

2005

Publisher:

Oxford University PressOxford

Abstract The spinning Earth is, of course, a timekeeper. The instantaneous position of the sun in the sky during the day, or of particular stars in the night sky, indicates a moment in time. Weather permitting, sundials could mark off daytime intervals as sequences of positions of the shadow cast by a stick or wedge (the gnomon). While timekeeping with devices of various descriptions (water clocks, burning candles, flowing sand) has a long history, for millennia accuracy was not a high priority. Human affairs were mainly local and exactness was not essential. Ultimately, however, the need for public timekeeping led to a progression of significant advances and inventions. The epoch of the first large mechanical clocks began around 1335 in Milan. Many towns and cities throughout Europe installed similar clocks in cathedrals and public squares. An example of an early English cathedral clock is the one at Salisbury (c.1275–1284) (Fig. 10.1).

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