The most conclusive proof, however, of the antiquity of Chaldæan science is afforded by the measures of time which were established prior to the commencement of history, and have come down to the present era in the days of the week and the signs of the zodiac. There can be no doubt that the first attempts to measure time beyond the single day and night, were lunar, and not solar. The phases of the moon occur at short intervals, and are more easily discerned and measured than those of the sun in its annual revolution. The beginning and end of a solar year, and the solstices and equinoxes are not marked by any decided natural phenomena, and it is only by long-continued observations of the sun's path among the fixed stars that any tolerably accurate number of days can be assigned to the duration of the year and seasons. But the recurrence of new and full moon, and more especially of the half-moons when dusk and light are divided by a straight line, must have been noted by the first shepherds who watched the sky at night, and have given rise to the idea of the month, and its first approximate division into four weeks of seven days each. Accordingly we find that in all primitive languages and cosmogonies the moon takes its name from a root which signifies "the measurer," while the sun is the bright or shining one. A relic of this superior importance of the moon as the measurer of time is found in the old Accadian mythology, in which the moon-god is masculine and the sun-god feminine, while with the Semites and other nations of a later and more advanced civilization, the sun is the husband, and the moon his wife. For as observations multiplied and science advanced, it would be found that the lunar month of twenty-eight days was only an approximation, and that the solar year and months defined by the sun's progress through the fixed stars afforded a much more accurate chronometer. Thus we find the importance of the moon and of lunar myths gradually superseded by the sun, whose daily risings and settings, death in winter and resurrection in spring, and other myths connected with its passage through the signs of the solar zodiac, assume a preponderating part in ancient religions. Traces, however, of the older period of lunar science and lunar mythology still survived, especially in the week of seven days, and the mysterious importance attached to the number 7. This was doubtless aided by the discovery which could not fail to be made with the earliest accurate observations of the heavens, that there were seven moving bodies, the sun, moon, and five planets, which revolved in settled courses, while all the other stars remained fixed. Scientific astrology, as distinguished from a mere superstitious regard of the flight of birds and other omens, had its origin in this discovery. The first philosophers who pondered on these celestial phenomena were certain to infer that motion implied life, and in the case of such brilliant and remote bodies divine