514 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1788. 



suggest, that the embolism is in fact applied so soon after the commencement of 

 the cycle, as the yearly accumulation of the fractional parts exceeds the sum of 

 half a day, or 1 2 hours, and that it accordingly is made to take place at the end 

 of the (2d year, because the fractions then amount to 17^ 36% or 22 parts in 

 30; at the end of the 5th year, because they then amount to 25; and at the 

 end of the 7th year, to 17 parts; keeping thus as near as possible to the mean 

 division of time, by applying the compensation before it is fully wanted. The 

 effect however is in both cases the same, and it is of but little moment to deter- 

 mine which theory is right. This cycle of 30 Mahometan years, contains 

 10,631 days, and is equal to 2Q years and 39 days of our computation. The 

 annual mean difference is 10 days and 21 hours nearly; which in common cal- 

 culations, for short periods of time, may be reckoned at 11 days, by which 

 number the lunar year anticipates the solar. 



Annexed is a table exhibiting the correspondence of the years of the Hejera, 

 from the establishment of that epoch, with those of the Christian era, to the 

 year of our Lord 2000. Until the beginning of the present century, it ap- 

 pears sufficient to distinguish every 10th year ; the intervals between which may 

 be calculated with ease and precision, by attending to what has been said res- 

 pecting the cycle. From the year 1700 to the conclusion of the 20th century, 

 for the convenience of historians yet unborn, the commencement of each year 

 of the Hejera is ascertained. 



Table exhibiting the Correspondence of the Years of the Hejera, with those of the Christian Era, 



IDay. 



31 Oct. 



14 July 

 27 Mar. 



9 Dec. 

 22 Aug. 



5 May 

 17 Jan. 

 29 Sept. 

 13 June 

 25 Feb. 



7 Nov. 

 22 July 



4 April 

 16 Dec. 

 29 Aug. 

 13 May 

 24 Jan. 



7 Oct. 

 21 June 



3 Mar. 



15 Nov. 

 29 July 

 11 AprU 



F 



Sa 



M 



W 



Th 



Sa 



M 



Tu 



Th 



Sa 



Su 



Tu 



Th 



F 



Su 



Tu 



W 



F 



Su 



M 



W 



F 



Sa 



