CHRONOLOGY. 43 



the quotient is 30 r \- , therefore, as the folar year 

 confifts of twelve months, feven of thefe 

 months mould have 30 days, and live 3 1 , and 

 when the year confifts of 366 days, there mould 



A months of 30 days, and fix of 31. Bur 

 in our chronology a different method is obferved. 

 In the common year, of 365 days, the months of 

 January, March, May, July, Auguft, Odlober 

 and December, have 3 1 days each ; thofe of 

 April, June, September, and November, 30 , 

 and the month of February 28 days: but when 

 the year confifts of 366 days, February has 29 

 days : fuch a year is called BifTextile, or Leap- 

 year, and the day that is added is called the In- 

 tercalary day. It is alfo necefiary to obferve, 

 that as the time above 365 days confifts of 5 

 hours 49 minutes, there will be in a century, be- 

 Cde the 24 intercalary days, a furplus of 5 hours 



40 minutes, which, in 400 years, will 

 amount to 22 hours 40 minutes, or almoft a day, 

 which mu ft therefore be alfo in ^d at the 



end of the fourth century. 



IX. The lunar year is compofcd of 12 lunar 

 months, and confifts of 354 days, 8 hours, 38 

 minutes, and 36 feconds : confequcntly the dif- 



;ce between the iolar and the lunar ;, 

 amounts to 10 days, 21 hours, 24 feconds. 

 Chronology therefore demonftrates, by the 

 of aftronomic calculation, that, in a hundred lu- 

 nar years, there muft be intercalated about 53 

 months , unlch> \vc would have the bcginnii 



