Another work compiled for the same library, and containing observations which started from a similarly fallacious theory, was one in seventy-two books on the pseudo-science of astrology, which was called “The Illumination of Bel.” But in this case the observations were not wholly useless. The study of astrology was intermixed with that of astronomy, of which Babylonia may be considered to be the birthplace. The heavens had been mapped out and the stars named; the sun’s course along the ecliptic had been divided into the twelve zodiacal signs, and a fairly accurate calendar had been constructed. Hundreds of observations had been made of the eclipses of the sun and moon, and the laws regulating them had been so far ascertained that, first, eclipses of the moon, and then, but with a greater element of uncertainty, eclipses of the sun, were able to be predicted. One of the chapters or books in the “Illumination of Bel” was devoted to an account of comets, another dealt with conjunctions of the sun and moon. There were also tables of observations relating to the synodic revolution of the moon and the synodic periods of the planet Venus. The year was divided into twelve months of thirty days each, an intercalary month being inserted from time to time to rectify the resulting error in the length of the year. The months had been originally called after the signs of the zodiac, whose names have come down to ourselves with comparatively little change. But by the side of the lunar year the Babylonians also used a sidereal year, the star Capella being taken as a fixed point in the sky, from which the distance of the sun could be measured at the beginning of the year, the moon being used as a mere pointer for the purpose. At a later date, however, this mode of determining time was abandoned, and the new year was made directly dependent on the vernal equinox. The month was subdivided into weeks of seven days, each of which was consecrated to a particular deity. These deities were further identified with the stars. The fact that the sun and moon, as well as the evening and morning stars, were already worshipped as divinities doubtless led the way to this system of astro-theology. But it seems never to have spread beyond the learned classes and to have remained to the last an artificial system. The mass of the people worshipped the stars as a whole, but it was only as a whole and not individually. Their identification with the gods of the state religion might be taught in the schools and universities, but it had no meaning for the nation at large.