In the Euphrates Valley, the heat during the dry season, from about May till November, when for weeks, and even months, no cloud is to be seen, beggars description; but strange enough, the Arabs who dwell there at present, while enduring the heat without much discomfort, are severely affected by a winter temperature that for Europeans and Americans is exhilarating in its influence.
From what has been said, it will be clear that the Euphrates is, _par excellence_, the river of Southern Mesopotamia or Babylonia, while the Tigris may be regarded as the river of Assyria.

It was the Euphrates that made possible the high degree of culture, that was reached in the south.

Through the very intense heat of the dry season, the soil developed a fertility that reduced human labor to a minimum.

The return for sowing of all kinds of grain, notably wheat, corn, barley, is calculated, on an average, to be fifty to a hundred-fold, while the date palm flourishes with scarcely any cultivation at all.

Sustenance being thus provided for with little effort, it needed only a certain care in protecting oneself from damage through the too abundant overflow, to enable the population to find that ease of existence, which is an indispensable condition of culture.