The general appearance of a Babylonian temple, or at any rate of its chief feature, the tower or ziggurat, will be best gathered from a more particular description of a single building of the kind; and the building which it will be most convenient to take for that purpose is that remarkable edifice which strikes moderns with more admiration than any other now existing in the country, and which has also been more completely and more carefully examined than any other Babylonian ruins—­the Birs-i-Nimrud, or ancient temple of Nebo at Borsippa.  The plan of this tower has been almost completely made out from data still existing on the spot; and a restoration of the original building may be given with a near approach to certainty. [PLATE XV., Fig. 1.]

[Illustration:  PLATE XV.]

Upon a platform of crude brick, raised a few feet above the level of the alluvial plain, was built the first or basement stage of the great edifice, an exact square, 272 feet each way, and and probably twenty-six feet in perpendicular height.  On this was erected a second stage of exactly the same height, but a square of only 230 feet; which however was not placed exactly in the middle of the first, but further from its northeastern than its south-western edge, twelve feet only from the one and thirty feet from the other.  The third stage, which was imposed in the same way upon the second, was also twenty-six feet high, and was a square of 188 feet.  Thus far the plan had been uniform and without any variety; but at this point an alteration took place.  The height of the fourth stage, instead of being twenty-six, was only fifteen feet.  In other respects however the old numbers were maintained; the fourth stage was diminished equally with the others, and was consequently a square of 146 feet.  It was emplaced upon the stage below it exactly as the former stages had been.  The remaining stages probably followed the same rule of diminution—­the fifth being a square of 104, the sixth one of 24, and the seventh one of 20 feet.  Each of these stages had a height of fifteen feet.  Upon the seventh or final stage was erected the shrine or tabernacle, which was probably also fifteen feet high, and about the same length and breadth.  Thus the entire height of the building, allowing three feet for the crude brick platform, was 150 feet.

The ornamentation of the edifice was chiefly by means of color.  The seven stages represented the Seven Spheres, in which moved (according to ancient Chaldaean astronomy) the seven planets.  To each planet fancy, partly grounding itself upon fact, had from of old assigned a peculiar tint or hue.  The Sun was golden, the Moon silver; the distant Saturn, almost beyond the region of light, was black; Jupiter was orange the fiery Mars was red; Venus was a pale Naples yellow; Mercury a deep blue.  The seven stages of the tower, like the seven walls of Ecbatana, gave a visible embodiment to these fancies.  The basement