This was accomplished by the erection of dikes, and by directing the waters through channels into the fields.
Assyria, more rugged in character, did not enjoy the same advantages.
Its culture, therefore, not only arose at a later period than that of Babylonia, but was a direct importation from the south.

It was due to the natural extension of the civilization that continued for the greater part of the existence of the two empires to be central in the south.

But when once Assyria was included in the circle of Babylonian culture, the greater effort required in forcing the natural resources of the soil, produced a greater variety in the return.

Besides corn, wheat and rice, the olive, banana and fig tree, mulberry and vine were cultivated, while the vicinity of the mountain ranges furnished an abundance of building material--wood and limestone--that was lacking in the south.

The fertility of Assyria proper, again, not being dependent on the overflow of the Tigris, proved to be of greater endurance.