The next stratum brings us to the period of Babylonian supremacy, when the viceroys of the Babylonian king ruled at Susa, and Semitic influence was already predominant in the Babylonian plain. It is the age of Sargon of Akkad, and its commencement may approximately be placed about B.C. 4000. The pottery still consists of a yellow paste, though there are also many specimens of a coarse black clay decorated with incrustations in white. The yellow ware is occasionally ornamented with mouldings of trees and other natural objects. A typical vase of the period is one of globular shape and small rim, and with a moulded or incised rope-pattern running round the centre and lower part of the rim. Another type is one which looks like an inverted vase, with a series of rope-patterns encircling it, while another seems to have been copied from the pile of cylindrical vases into which, as into a drain, the body of the dead Babylonian was inserted. These types of vase appear to have lasted, with little variation, down to the end of the Persian period, though, unfortunately, the disturbance of the ground and the consequent mixture of objects under the temple of In-Susinak, where the excavations were carried on, makes certainty on the point unattainable. Immense quantities of bronze votive offerings, of all kinds and sorts, were, however, found here, along with fragments of glass, and, as inscriptions show that they must all have been buried on the spot before the tenth century B.C., we have a time-limit for dating the forms of the bronze weapons and tools. The archæological evidence obtained at Susa has been supplemented by excavations made some ninety miles to the west of it, at a place called Mussian, on the eastern bank of the river Tib. Here there are graves, as well as the remains of a temple and houses with vaults, columns and walls of burnt brick. Where the strata have allowed a section to be cut down to the virgin soil the results are found to agree with those revealed by the excavations at Susa. The earliest layer belongs to the neolithic age, flint and obsidian, as at Susa, being the materials employed for tools and weapons. The pottery is thick and hand-made, the paste being either yellow or red in colour, and the surface is often polished, while many of the vases are furnished with holes for suspension. This layer seems older than anything discovered at Susa. It is followed by a second layer, in which the pottery is wheel-made, and is decorated with animal and vegetable figures in black or red, like the first prehistoric ware of the Susa mounds. Among the animal figures are those of men, and one fragment of yellow ware is ornamented with the so-called swastika. In the upper part of the layer a few fragments of copper have been met with, indicating that the neolithic age was beginning to pass into that of copper.