What is a Chaldean astronomical period or cycle, the length of which has been variously estimated from 3,600 years to 3,600 days, or a little short of 10 years. Brande & C called?

saros — A Chaldean astronomical period or cycle, the length of which has been variously estimated from 3,600 years to 3,600 days, or a little short of 10 years. Brande & C. (Webster's 1913.)

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