ZIGGURAT RESTORED (Perrot and Chipiez), THE TOWER OF BABEL.

It may be affirmed of all these ziggurats that they were not tombs like the Egyptian pyramids, but were erected exclusively for astronomical and astrological purposes. The number of stages had always reference to some religious or astronomical fact, as three to symbolize the great triad; five for the five planets; or seven for these and the sun and moon; the number of seven being never exceeded, and the order the same as that adopted for the days of the week, viz. according to the magnitudes of their respective orbits. They were oriented with as much care as the pyramids, which is of itself a proof that they were used as observatories, but with this difference, that their angles instead of their faces were directed towards the true north and south. To this rule there are only two exceptions, probably of late date after Egyptian influences had been introduced, but the original and national ziggurats invariably observe the rule of pointing angles and not sides to the four cardinal points. This is a remarkable fact as showing that the astronomies of Egypt and Chaldæa were not borrowed one from the other, but evolved independently in prehistoric times. An explanation of it has been found in the fact recorded on a geographical tablet, that the Accadians were accustomed to use the terms north, south, east, and west to denote, not the real cardinal points, but countries which lay to the N.W., S.E., and S.W. of them. It is inconceivable, however, that such skilful astronomers should have supposed that the North Pole was in the north-west, and a more probable explanation is to be found in the meaning of the word ziggurat, which is holy mountain.

It was a cardinal point in their cosmogony that the heavens formed a crystal vault, which revolved round an exceedingly high mountain as an axis, and the ziggurats were miniature representations of this sacred mountain of the gods. The early astronomers must have known that this mountain could be nowhere but in the true north, as the daily revolutions of the heavenly bodies took place round the North Pole. It was natural, therefore, that they should direct the apex or angle of a model of this mountain rather than its side to the position in the true north occupied by the peak of the world's pivot.

Be this as it may, the fact that the ziggurats were carefully oriented, and certainly used as observatories at the earliest dates of Chaldæan history, is sufficient to prove that the priestly astronomers must have already attained an advanced knowledge of science, and kept an accurate record of long-continued observations. This is fully confirmed by the astronomical and astrological treatise compiled for the royal library of Sargon I., date 3800 b.c., which treats of eclipses, the phases of Venus, and other matters implying a long previous series of accurate and refined astronomical observations.

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 life; and that as the sun and moon exerted such an obvious influence on the seasons and other human affairs, so probably did the other planets or the gods who presided over them. The names and order of the days of the week, which have remained so similar among such a number of ancient and modern nations, show how far these astrological notions must have progressed when they assumed their present form, for the order is a highly artificial one.

Why do we divide time into weeks of seven days, and call the days Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday, and why are these names of special planets, or of the special gods associated with them, identical, and occur in the same order among so many different nations? For whether we say Thor's-day or Jove's-day, and call it " Thursday" or "Jeudi," the same god is meant, who is identified with the same planet, and so for the others. It is quite clear that the names of the seven days of the week were originally taken from the seven planets—i.e. from the seven celestial bodies which were observed by ancient astronomers to move, and, therefore, be presumably endowed with life, while the rest of the host of heaven remained stationary. These bodies are in order of apparent magnitude:—