A Mathematical and Philosphical Dictionary
, an extent of three miles in length. A nautical league, or three nautical miles, is the 20th part of a degree of a great circle.
LEAP-Year, the same as BISSEXTILE; which see. It is so called from its leaping a day more that year than in a common year; consisting of 366 days, and a common year only of 365. This happens every 4th year, except only such complete centuries as are not exactly divisible by 4; such as the 17th, 18th, 19th, 21st &c. centuries, because 17, 18, 19, 21, &c, cannot be divided by 4 without a remainder.
To find Leap Year, &c. Divide the number of the year by 4; then if o remain, it is leap-year; but if 1, 2, or 3 remain, it is so many after leap-year.
Or the rule is sometimes thus expressed, in thesetwo memorial verses: Divide by 4; what's left shall be, For leap-year o; for past, 1, 2, or 3.
Thus if it be required to know what year 1790 is: then 4) 1790 (447 2 remains:
so that 2 remaining, shews that 1790 is the 2d year after leap-year. And to find what year 1796 is: then 4) 1796 (449 here o remaining, shews that 1796 is a leap-year.