But neither the Babylonians nor the Assyrians confined themselves exclusively to the use of clay and calcareous stone as the material whereon to write their inscriptions. Sometimes the hardest volcanic rocks were employed for the purpose, doubtless in consideration of their durability and power of resisting the devastating influences of time and climate. Thus in the course of the German excavations at Babylon a plate of dolerite measuring about a foot and a half square and bearing an inscription of Adad-nirari the son of Ashur-dan was discovered. So too Dungi and Bur-Sin, kings of Ur (_circ._ 2350 B.C.), have left us inscriptions chiselled on hard diorite, the inscriptions themselves being of a votive character, while a club-button made of the same material and bearing an inscription of ten lines was found at Babylon. The various statues and stelæ made of these hard igneous stones and found both in Assyria and Babylonia, though more frequently in the mother country, practically always bear an inscription. A good example of an Assyrian inscription on basalt is that found on the basalt statue of Shalmaneser II (860-825 B.C.), which was brought to light in the course of the recent excavations conducted by the Deutsche Orient-Gesellschaft at Ashur. Again the numerous stone gate-sockets discovered in the ruins of early buildings in Babylonia are nearly all inscribed with the name and titles of the person who erected the building, and sometimes the original inscription has been erased or obliterated to make room for the inscription of a later ruler, who knowing full well the difficulty of procuring stone in the low-lying country of Babylonia, was not so short-sighted as to cast away the gate-sockets of his vanquished predecessor, but on the contrary utilized them for his own new building. Thus for example the gate-socket of Lugal-kigub-nidudu, an early king of Sumer, was subsequently used by Shar-Gâni-sharri, king of Akkad, in the construction of his temple at Nippur.