The method employed in very early times in Assyria and Babylonia for determining the first month of the year was a simple and effective one, the principle of which may be explained thus: If we watch for the appearance of the new moon in spring time, and, as we see it setting in the west, notice some bright star near it, then 12 months later we should see the two together again; but with this difference, that the moon and star would be seen together, not on the first, but on the second evening of the month. For since 12 lunar months fall short of a solar year by 11 days, the moon on the first evening would be about 11 degrees short of her former position. But as she moves about 13 degrees in 24 hours, the next evening she would practically be back in her old place. In the second year, therefore, moon and star would set together on the second evening of the first month; and in like manner they would set together on the third evening in the third year; and, roughly speaking, on the fourth evening of the fourth year. But this last conjunction would mean that they would also set together on the first evening of the next month, which would thus be indicated as the true first month of the year. Thus when moon and star set together on the third evening of a month, thirteen months later they would set together on the first evening of a month. Thus the setting together of moon and star would not only mark which was to be first month of the year, but if they set together on the first evening it would show that the year then beginning was to be an ordinary one of 12 months; if on the third evening, that the year ought to be a full one of 13 months. This was precisely the method followed by the Akkadians some 4000 years ago. For Prof. Sayce and Mr. Bosanquet translate an old tablet in Akkadian as follows:-- "When on the first day of the month _Nisan_ the star of stars (or _Dilgan_) and the moon are parallel, that year is normal. When on the third day of the month _Nisan_ the star of stars and the moon are parallel, that year is full."[315:1] The "star of stars" of this inscription is no doubt the bright star Capella, and the year thus determined by the setting together of the moon and Capella would begin on the average with the spring equinox about 2000 B.C. When Capella thus marked the first month of the year, the "twin stars," Castor and Pollux, marked the second month of the year in just the same way. A reminiscence of this circumstance is found in the signs for the first two months; that for the first month being a crescent moon "lying on its back;" that for the second month a pair of stars.