424 Mr. Marsden the Era ef 
inftead of the 1 6th, or hiftoricai period, it was judged requi- 
site to add one day, throughout, to his calculations. The pro- 
priety of this alteration is ftrengthened by the authority of 
other chronologies and by the practice of the modern alma- 
nacs •f*. It is alfo to be obferved, that the tables of Gra- 
vius, having been compofed in the Seventeenth century, are 
calculated both for paft and future time, according to the old 
Style ; and as the change took place, in England, in September 
of the year 1752, it was neceftary to ad juft all the Succeeding 
years to the new calendar. I11 order that a judgment may be 
formed of the correspondence of the annual periods Ihewn by 
thefe tables, founded on the cycle of thirty years, which is 
adjufted to the mean motion of the moon, with tbofe marked 
by the appearance of that planet, a (hort table is Subjoined, 
containing a comparison of the refults of the two modes of 
reckoning, during one cycle, commencing with the year of 
the Hejera 1 1 7 1 (/>). 
* See Tables of the Hejeni in RicCioli, Chronologia Reformata, 1659* 
Ephemerides Mat. Fred. Beckii, 1695 (c). 
f According to the original tables of Greaves, the firft day of Moharram, 
in the year of Christ 1783, falls on the 14th November, O.S., or 25th 
November, N.S. ; and in 1784, on the 2d November, O.S., or 13th November, 
N.S. ; whereas, by two almanacs, printed at Calcutta in Bengal, it appears, 
that the days fliould be the 26th and 14th November. Of thefe almanacs, the 
one was compiled in the “ Office of the Million;” and the other by an ingenious 
aftronomer from England ; and both founded on the ufage of the Mahometans of 
India, 
1 
A U* 
