Speaking in round numbers, from 4,000 to 2,000 B.C., the winter solstice took place when the sun was in conjunction with the constellation Aquarius, which constellation, or some one of its stars, was, as has been suggested, called by the Babylonian astronomers, Gula, Gula being another name for Bau. It is not therefore surprising to find that those rulers of Lagash, whose dates fell between 4,000 and 2,000 B.C., should have so often associated together Ningirsu and Bau; and further, that Gudea, whose rule is placed at about 2,900 B.C., should on “the day of the beginning of the year” have kept high festival in honour of Bau, as the beneficent deity presiding in conjunction with Ningirsu over the revolving years. The precession of the equinoxes must necessarily in the course of ages introduce confusion into all Zodiacal calendars, and into all ritual and mythological symbolism founded on such calendars. From 2,000 b.c. down to the beginning of our era, the winter solstice took place when the sun was in conjunction with Capricornus, not with Aquarius. In those later days, if the inhabitants of Lagash still celebrated their new year’s festival at the winter solstice, Bau (= Gula = Aquarius) could only have laid a traditional claim to preside over it. In accordance with these astronomical facts, we learn from the teachings of the tablets that the especial reverence paid to Bau = Gula, in the Lagash inscriptions was not extended to her in later times. As to Ninib, we know that even at Gudea’s date in the neighbouring state of Accad, and in later times in Babylon, he did not hold the pre-eminent position accorded to him by the early rulers of Lagash. This difference in the religious observances of Accad and Lagash regarding Ninib--if we suppose him to be the god of the winter solstice--may also receive an astronomical explanation. According to the evidence of _The Standard Astrological Work_, the compilation of which is generally attributed to the date 3,800 B.C., and according to the evidence of many other tablets, the year in Accad and afterwards in Babylon began not at the winter solstice, but on the 1st day of Nisan, and Nisan (Acc. Bar zig-gar), the month of “the sacrifice of righteousness,” was, as its name suggests, the month during which the sun was in conjunction with the constellation Aries. At Gudea’s date, about 2,900 B.C., the 1st of Nisan, if it was dependent on the sun’s entry into Aries, must have fallen about midway between the winter solstice and the spring equinox, and as century succeeded century, the 1st of Nisan must slowly but surely have receded further from the solstice and have approached more and more to the equinoctial point.