A new historical relation of the kingdom of Siam by Monsieur De La Loubere ... ; done out of French, by A.P. Gen. R.S.S.
La Loubère, Simon de, 1642-1729., A. P.

XIX. An Ancient Astronomical Epocha of the Indians.

IN the III. Chapter of these Reflexions we have remarked, that the Siameses in their dates make use of an Epocha, which precedes the year of Jesus Christ by 544 years, and that after the twelfth or thirteenth month of the years from this Epocha, which do now end in November or December, the first month which fol∣lows, and which must be attributed to the following year, is yet attributed to the same year: which has given us ground to conjecture, that they attribute also to the same year, the other months to the beginning of the Astronomical year, which begins at the Vernal Equinox. This conjecture has been confirm∣ed by the report of Mr. de la Loubere, who likewise judges that this Ancient Epocha must also be an Astronomical Epocha.

The extraordinary manner of computing the first and second month of the same year after the twelfth or thirteenth, may cause a belief that the first month of these years, which begins at present in November or December, began anciently near the Vernal Equinox, and that in process of time, the Indians, either thro negligence, or to make use of a Cycle too short, as would be that of 60 years which the Chineses do use, have sometimes failed to add a thirteenth month to the year which ought to be Embolismick, whence it has happen'd that the first month has run back into the winter; which having been perceived, the winter months, now called first, second and third, have been attributed to the prece∣ding year, which according to the ancient institution ought not to end but at Spring.

Thus the Indian year, which was called 2231, at the end of the year 1687 of Jesus Christ, ought not to end, according to the Ancient Institution, till the Spring of the year 1688. Having substracted 1688 from 2231, there remains 543, which is the number of the compleat years from the ancient Epocha of the Indians, to the year of Jesus Christ. This Epocha appertains therefore to the cur∣rent year 544 before Jesus Christ, according to the most common way of com∣puting.

In this year the middle conjunction of the Moon happened between the true Equinox, and the middle Equinox of the Spring, at 15 degrees distance from the North Node of the Moon, the 27th of March, according to the Julian form, a Saturday, which is an Astronomical Epocha almost like to that of the year 638, which has been chosen, as more modern and more precise than the former.

Between these two Indian Epocha's there is a period of 1181 years, which be∣ing joyned to a period of 19 years, there are two periods of 600 years, which reduce the new Moons near the Equinoxes.