MEASURE OF TIME. 27 



noting leap years are exactly divisible by 4 ; as, 1856, 1860, 

 1864 ; except years whose number can be divided without a 

 remainder by 100, but not by 400. 



2. Owing to an error in the Julian calendar, it was de- 

 creed by the British Government that the day following 

 the second day of September, 1752, should be called the 

 fourteenth day of September, or that 11 days should be 

 stricken from the calendar. 



3. Time, previous to this decree, is called Old Style (O. S.), 

 and since, New Style (N. S.). Russia still reckons time by 

 the Old Style, hence their dates are 12 days behind ours. 



4. In most business transactions 30 days are called a 

 month, and 52 weeks a year. 



5. The centuries are numbered from the commencement 

 of the Christian era ; the months from the commencement 

 of the year ; the days from the commencement of the 

 month ; and the hours from the commencement of the day 

 (12 o'clock, midnight), and from mid-day or noon. A.M. 

 denotes time before noon, M., at noon, and P.M., after noon. 

 Thus, 9 o'clock A.M., May 23, 1860, is the end of the ninth 

 hour of the 23d day of the fifth month of the 60th year of 

 the 19th century. 



6. A decade is a period of 10 years. 



7. The Lunar Cycle, or Golden Number, is a period of 

 19 years, after which the changes of the moon return on the 

 same davs of the month. 



Of THE 



UNIVERSITY 



OF 



