When they made the first clocks, how did they know whether they were accurate?

Question

They had nothing to compare the clocks against, and I don’t think the stars and the sun would have made an useful target for comparison.

In: 17

Answer 1

The first clocks were accurate per definition. Sundials tracked the Sun’s position in the sky, and the time they showed *was* the correct time (i.e. if it marked “noon”, it was noon), because that was the time. Keep in mind that the idea of having hours of the same length is more recent, the first divisions of the day were proportional to how much it took from sunrise to sunset, so in summer “hours” were longer than in winter.