We have dug out the ancient building to a considerable depth, especially on the north and south sides. The bricks are of the small size (32 × 32 centimetres), and bear no stamp. They are laid in asphalt and reeds and are crushed and split in every direction. The wall surfaces are daubed over with asphalt, which also covers the split and damaged portions, and thus we have ample evidence of the handiwork of the restorer. On the north side Nebuchadnezzar added to the foundations of the chambers a strengthening length of rubble wall laid with asphalt and reeds, which faced the north front for a breadth of about 10 metres. The ancient wall rises to a height of about 7 metres above zero (see p. 167). Above this lie the usual 33–centimetre bricks with Nebuchadnezzar’s 4–lined stamp, also laid in asphalt and reeds, with the border courses laid in mud. In the lower courses of the later building a number of tiles measuring 44 × 44 × 6 centimetres are built into the wall, which can be recognised with certainty as having been previously used as flagstones by the fragments of gypsum mortar that still adhere to their joints, and show that Nebuchadnezzar very naturally took up the pavement of Nabopolassar, and used it in part as material for the walls. His new pavement consists of ten courses of brick laid in asphalt alone, covered with a layer of brick rubble, over which paving-stones measuring 38·5 × 38·5 are laid. Of this pavement, however, we have found little more than a small piece, which still remains in the southern chambers. This later pavement was apparently higher than the old one, but 7 metres lower than that in the great eastern portion. Of the final alterations that brought the whole up to one and the same level there are only traces, for instance, the building by which the principal hall adjoining the Western Court (W) was enlarged. [Illustration: FIG. 68.—Space between the Nabopolassar Palace and Citadel wall, on the south. ] The ancient palace comes to an end at the squaring line _i_ of Fig. 44. Originally it extended farther, and the wall that faces west was here chipped off, when the portion farthest to the west was added. On the south, on the contrary, the ancient palace wall still stands and is distinctly escarped (Fig. 68). Here Nebuchadnezzar jointed his brickwork with a grid-like insertion of beams of poplar wood laid lengthways and crossways to strengthen it. The foundations of the adjoining chambers have also a filling of broken brick to the east and of mud brick to the west.