It has been remarked that most of them were broken into small pieces, as though by some invader of the country; but this was not the case with certain gate-sockets and great blocks of diorite which were too hard and big to be easily broken. Moreover, any conqueror of a city would be unlikely to spend time and labour in destroying materials which might be usefully employed in the construction of other buildings which he himself might erect. Stone could not be obtained in the alluvial plains of Babylonia and had to be quarried in the mountains and brought great distances. [Illustration: 188.jpg STONE GATE] Stone Gate-Socket Bearing An Inscription of Uk-Engur, An Early King of The City Of Ur. Photograph by Messrs. Mansell & Co. From any building of his predecessors which he razed to the ground, an invader would therefore remove the gate-sockets and blocks of stone for his own use, supposing he contemplated building on the site. If he left the city in ruins and returned to his own country, some subsequent king, when clearing the ruined site for building operations, might come across the stones, and he would not leave them buried, but would use them for his own construction. And this is what actually did happen in the case of some of the building materials of one of these early kings, from the lower strata of Nippur. Certain of the blocks which bore the name of Lugalkigubnidudu had been used again by Sargon, King of Agade, who engraved his own name upon them without obliterating the name of the former king.