576 Mr. Marsden on the 
from no very circumflantial data, inferred that it muff have 
had for its epoch a mean conjunction of the fun and moon, 
which happened on 21ft March, 638 of the Chriftian era. 
This preceded by a few hours the commencement of the efta- 
blifhed Hindoo year, to which it was evidently meant to be 
accommodated, though it is by him referred to the vernal equi- 
nox, which took place two days earlier (w). The length of 
the Siamefe folar year he found to be 365 d. 6 h. 12' 36" (*), 
and confequently 1152 years of the era fhould expire on the 
nth April, 1790, when the fun enters the Indian zodiac, being 
560 years later than the era of Salabdn. For want of corro- 
borating fads, this determination of an epoch by M. Cassini 
was confidered as fpeculative and uncertain ; but I am acciden- 
tally in poffeffion of a date, which, though not precife, may 
ferve generally to authenticate it. “ In 1769, the king of 
Pegu (a country bordering on Siam , and formerly conquered 
by it) dates his letter to the French at Pondicherry, the 12th 
of the month Kchong 1132.” This makes 1790 to correfpond 
with 1153 inftead of 1152; but when we confider the vague 
manner in which notices of this kind are given, a difference of 
one year can fcarcely be urged as an objedion. 
The Siamefe were alfo accuflomed to make ufe of a cycle of 
fixty years, expreffed by a repetition of twelve names of cer- 
tain animals, which, I obferve, are for the moft part the 
fame with thofe employed, for the fame purpofe, by the Chi- 
nefe and Mogul Tartars, from whom we may conclude it has 
been borrowed (y) ; but the meager and unfatisfadory exam- 
ples of its application, furnifhed by M. Loubere and P. 
Tachard, do not afford us the means of determining at what 
time they began to reckon their cycle. It appears only that the 
2 year 
