the Mahometans , called the Hejera . 417 
Arabs beginning their day at fun-fet ; conformably with which 
idea, the time when the moon became vifible at Mecca, being 
the evening of Thurfday the fifteenth, according to our mode 
of computation*, was to them the commencement of Fri- 
day; which Friday (beginning a few hours later) we term the 
fixteenth of July. At that period the cycle of the fun was 
15; the cycle of the moon, or golden number, 15; the FvO- 
man indidtion 10 ; and the dominical letter C. 
The year of the Mahometans conlifts of twelve lunar 
months, and no embolilm being employed to ad juft it 
to the folar period (as pratftifed by the Chaldaaans and He- 
brews, who were in other particulars their guides, and an- 
ciently, it is faid, by the Arabs themfelves), the commence- 
ment of each fucceffive lunar year anticipates the completion 
of the folar, and revolves through all its feafons, the months 
reflectively preferving no correfpondence (g). 
In order to form a juft and accurate idea of the length of 
this year, and of its component months, it will be neceftary 
to diftinguifh two modes of eftimating their commencement 
and duration. Thefe, though their difference is not progref- 
live (never amounting to more than two whole days, and 
rarely to fo much as one), may yet, if mifunderftood, occa- 
fton, in fome inftances, uncertainty' and error: and more efpe- 
cially as the writers on this fubjeCt have inadvertently fallen 
* The new moon happened in July 622, on the 14th day, at 5J hours, 
A.M. Greenwich time, or about 8 hours Mecca time; and at fun-fet of the 
fame day, the moon was 5! degrees before the fun in longitude, and in 40 
minutes fouth latitude, and therefore about 4! degrees above the horizon. On 
the 15th, at fun-fet, it was iS 5 before the fun in longitude, in 37' north lati- 
tude, and about 15°! above the horizon, confequently vifible with clear weather. 
The fun fets at Mecca, on the 15th July, at 6 h, 4c/, and the twilight is there 
confiderably (horter than in the high latitudes. 
into 
