Ancient calendars and constellations

by Emmeline M. Plunket

6th month, Ki Gingir-na (“the errand of Istar”), Virgo.

We know from the Epping and Strassmaier tablets as a matter of fact, that the months and the constellations of the Zodiac did in the second century, B.C., correspond with each other in order and sequence as above suggested, and if further research should establish the fact that they so corresponded in Sargon’s time, then as we find Nisan (Bar zig-gar) throughout all these ages holding the place of “first month,” and marking “the beginning of the year,” it will necessarily follow that the Accadian, Babylonian, and Assyrian calendars dealt with a sidereal and not a tropical year.

Ours is a tropical year, that is to say, according to the Julian calendar (afterwards amended by Pope Gregory) it is bound to the seasons, and its months maintain a constant relation to the four great divisions of the ecliptic, i.e. the solstices and the equinoxes. The winter solstice always falls about the 22nd of December, the spring equinox about the 21st of March, the summer solstice about the 21st of June, and the autumnal equinox about the 23rd of September.

But (as has been suggested) the Accadian year was a sidereal year, and its months maintained a constant relation to the twelve star-marked divisions of the ecliptic, or, as they are called, the constellations of the Zodiac. Nisan always corresponded (as closely as a lunar month might) to the time during which the sun traversed the constellation Aries; Airu to the time during which it traversed the constellation Taurus; and so on through the twelve months of the year.

The equinoctial points are, however, always, though slowly, changing their position amongst the twelve constellations of the ecliptic. The months, therefore, which in 3,800 B.C., and still in the second century B.C., corresponded to the same star-groups, as above noted, must have held in different ages very different positions in regard to the four great divisions or seasons of the year.

We find in the tablets translated by Epping and Strassmaier the year “beginning with Nisan, hence in the spring,” and this seems a more or less natural season from which to count the year; but when, taking the precession of the equinoxes into account, we find that the year in Ḫammurabi’s time (2,200 B.C.) must have commenced one month, and in Sargon’s time (3,800 B.C.) two months before the spring equinox, we feel surprised and perplexed to find that the year must then have begun without any reference to the seasons—the four great and most easily observed divisions of the ecliptic.

It is difficult to imagine that the astronomers who so skilfully divided the ecliptic into its twelve parts, and who originated the wonderful Accadian calendar—a calendar so well thought out that, as we have seen reason to believe, it resisted all the shocks of time for nearly four thousand years—it is difficult to imagine that such astronomers should have taken no note of the four prominent divisions of the year and of the ecliptic, i.e. the solstices and the equinoxes.

PLATE I.

FIG. 1.