the Mahometans , called the Hejera. 42 ? 
and it is of but little moment to determine which theory is 
right *. 
This cycle of thirty Mahometan years, contains 10,631 days, 
and is equal to 29 years and 39 days of our computation. The 
annual mean difference is 10 days and 21 hours nearly; which 
in common calculations, for Ihort periods of time, may be 
reckoned at 1 1 days, by which number the lunar year antici- 
pates the folar. 
Annexed hereto is a table exhibiting the correfpondence of 
the years of the Hejera, from the eftablifhment of that epoch, 
with thofe of the Chriftian era, to the year of our Lord 2000. 
Until the beginning of the prefent century, it appears fuffi- 
cient to diftinguifh every tenth year ; the intervals between 
which may be calculated with eafe and precilion, by attending 
to what has been faid refpedting the cycle. From the year 
1700 to the conclufion of the twentieth century, for the con- 
venience of hiftorians yet unborn, the commencement of each 
year of the Hejera is afeertained. Thefe tables are founded 
upon thofe of Gravius (J. Greaves), in his Epochs cele- 
briores Ulug Beigi, publifhed in 1650; but as he, in con- 
formity with the principles of this celebrated Tartarian aftro- 
nomer t» has fixed the epoch of the Hejera to the 1 5th July, 
* The former hypothefis is fupported by Christmannus (Commentarius ad 
caput primum Alfragani, 1590), who quotes many ancient authorities. Peta- 
v jus (Peteau) (de Doftrina Temporum, 1627) is inclined to give the preference 
to the latter, on the authority of Paulus Forosempronius, and the probability 
of the matter («). It does not appear at what time the ufe of this cycle was intro- 
duced, but probably fubfeqnent to the eftablifhment of the era by Omar, though 
he is faid to have been affifted on that occafion by a learned Perfian. 
f Ulug Beig was the grandfon of Timur the Great (Tamerlane), to vvhofe 
empire he fucceeded on the death of his father Shah Rukh. He was born in 
1393, and died in 1449. 
inflead 
