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 meridian is the imaginary north-south line in the sky dividing east and west. Local noon time was originally (before clocks) defined as the time that the sun crossed the meridian. This definition of a day is a very precise 24 hours, to a very small fraction of a second, no matter what season.