Of the general arrangement of the royal palaces, of their height, their number of stories, their roofing, and their lighting, we know absolutely nothing.  The statement made by Herodotus, that many of the private houses in the town had three or four stories, would naturally lead us to suppose that the palaces were built similarly; but no ancient author tells us that this was so.  The fact that the walls which exist, though of considerable height, show no traces of windows, would seem to imply that the lighting, as in Assyria, was from the top of the apartment, either from the ceiling, or from apertures in the part of the walls adjoining the ceiling.  Altogether, such evidence as exists favors the notion that the Babylonian palace, in its character and general arrangements, resembled the Assyrian, with only the two differences, that Babylonian was wholly constructed of burnt brick, while in the Assyrian the sun-dried material was employed to a large extent; and, further, that in Babylonia the decoration of the walls was made, not by slabs of alabaster, which did not exist in the country, but mainly—­almost entirely—­by colored representations upon the brickwork.

Among the adjuncts of the principal palace at Babylon was the remarkable construction known to the Greeks and Romans as “the Hanging Garden.”  The accounts which, Diodorus, Strabo, and Q. Curtius give of this structure are not perhaps altogether trustworthy; still, it is probable that they are in the main at least founded on fact.  We may safely believe that a lofty structure was raised at Babylon on several tiers of arches, which supported at the top a mass of earth, wherein grew, not merely flowers and shrubs, but trees of a considerable size.  The Assyrians had been in the habit of erecting structures of a somewhat similar kind, artificial elevations to support a growth of trees and shrubs; but they were content to place their garden at the summit of a single row of pillars or arches, and thus to give it a very moderate height.  At Babylon the object was to produce an artificial imitation of a mountain.  For this purpose several tiers of arches were necessary; and these appear to have been constructed in the manner of a Roman amphitheatre, one directly over another so that the outer wall formed from summit to base a single perpendicular line.  Of the height of the structure various accounts are given, while no writer reports the number of the tiers of arches.  Hence there are no sufficient data for a reconstruction of the edifice.

Of the walls and bridge of Babylon, and of the ordinary houses of the people, little more is known than has been already reported in the general description of the capital.  It does not appear that they possessed any very great architectural merit.  Some skill was shown in constructing the piers of the bridge, which presented an angle to the current and then a curved line, along which the water slid gently. [PLATE XV., Fig. 3.] The loftiness of the houses, which were of three or four stories, is certainly surprising, since Oriental houses have very rarely more than two stories.  Their construction, however, seems to have been rude; and the pillars especially—­posts of palm, surrounded with wisps of rushes, and then plastered and painted—­indicate a low condition of taste and a poor and coarse style of domestic architecture.