4. Some eighteen miles further on (a day's march) the Greeks came to another great deserted city, which Xenophon calls Mespila. It had a similar but still higher wall. This city, he tells us, had also been inhabited by Medes, and taken by the king of Persia. Now these curious ruins were all that was left of Kalah and Nineveh, the two Assyrian capitals. In the short space of two hundred years, men had surely not yet lost the memory of Nineveh's existence and rule, yet they trod the very site where it had stood and knew it not, and called its ruins by a meaningless Greek name, handing down concerning it a tradition absurdly made up of true and fictitious details, jumbled into inextricable confusion. For Nineveh had been the capital of the Assyrian Empire, while the Medes were one of the nations who attacked and destroyed it. And though an eclipse of the sun--(the obscuring cloud could mean nothing else)--did occur, created great confusion and produced important results, it was at a later period and on an entirely different occasion. As to "the king of Persia," no such personage had anything whatever to do with the catastrophe of Nineveh, since the Persians had not yet been heard of at that time as a powerful people, and their country was only a small and insignificant principality, tributary to Media. So effectually had the haughty city been swept from the face of the earth! 5. Another hundred years brought on other and even greater changes. The Persian monarchy had followed in the wake of the empires that had gone before it and fallen before Alexander, the youthful hero of Macedon. As the conqueror's fleet of light-built Grecian ships descended the Euphrates towards Babylon, they were often hindered in their progress by huge dams of stone built across the river. The Greeks, with great labor, removed several, to make navigation more easy. They did the same on several other rivers,--nor knew that they were destroying the last remaining vestige of a great people's civilization,--for these dams had been used to save the water and distribute it into the numerous canals, which covered the arid country with their fertilizing network. They may have been told what travellers are told in our own days by the Arabs--that these dams had been constructed once upon a time by Nimrod, the Hunter-King. For some of them remain even still, showing their huge, square stones, strongly united by iron cramps, above the water before the river is swollen with the winter rains.