*** The tablets in which it is preserved for us come partly from the library of Assurbanipal at Nineveh, partly from that of the temple of Nebo at Borsippa; these latter are more recent than the others, and seem to have been written during the period of the Persian supremacy. Like the Egyptian civilization, it had had its birth between the sea and the dry land on a low, marshy, alluvial soil, flooded annually by the rivers which traverse it, devastated at long intervals by tidal waves of extraordinary violence. The Euphrates and the Tigris cannot be regarded as mysterious streams like the Nile, whose source so long defied exploration that people were tempted to place it beyond the regions inhabited by man. The former rise in Armenia, on the slopes of the Niphates, one of the chains of mountains which lie between the Black Sea and Mesopotamia, and the only range which at certain points reaches the line of eternal snow. At first they flow parallel to one another, the Euphrates from east to west as far as Malatiyeh, the Tigris from the west towards the east in the direction of Assyria. Beyond Malatiyeh, the Euphrates bends abruptly to the south-west, and makes its way across the Taurus as though desirous of reaching the Mediterranean by the shortest route, but it soon alters its intention, and makes for the south-east in search of the Persian Gulf. The Tigris runs in an oblique direction towards the south from the point where the mountains open out, and gradually approaches the Euphrates. Near Bagdad the two rivers are only a few leagues apart. However, they do not yet blend their waters; after proceeding side by side for some twenty or thirty miles, they again separate and only finally; unite at a point some eighty leagues lower down. At the beginning of our geological period their course was not such a long one. The sea then penetrated as far as lat. 33 deg., and was only arrested by the last undulations of the great plateau of secondary formation, which descend from the mountain group of Armenia: the two rivers entered the sea at a distance of about twenty leagues apart, falling into a gulf bounded on the east by the last spurs of the mountains of Iran, on the west by the sandy heights which border the margin of the Arabian Desert.* They filled up this gulf with their alluvial deposit, aided by the Adhem, the Diyaleh, the Kerkha, the Karun, and other rivers, which at the end of long independent courses became tributaries of the Tigris. The present beds of the two rivers, connected by numerous canals, at length meet near the village of Kornah and form one single river, the Shatt-el-Arab, which carries their waters to the sea. The mud with which they are charged is deposited when it reaches their mouth, and accumulates rapidly; it is said that the coast advances about a mile every seventy years.** In its upper reaches the Euphrates collects a number of small affluents, the most important of