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

How accurate did they need to be?

You could probably point to multiple times in history where clocks finally became accurate enough to be used in certain applications [https://en.wikipedia.org/wiki/Longitude_(book)](https://en.wikipedia.org/wiki/Longitude_(book)) is a book about a timepiece being made accurate enough for navigation in the 18th century.

I can imagine they had multiple timekeeping breakthroughs in the 20th century.