The change (which took place under the Popedom of Gregory XIII ) consisted in the omission of ten nominal days after the 4th of October, 1582 (so that the next day was called the 15th, and not the 5th), and the promulgation of the rule already explained for future regulation.” It will appear from the verse of Dante, that this error and its consequences had been noticed a century earlier than the year mentioned by Herschel. Dante speaks ironically; naming a very long period, and meaning a very short one. ↩