In most parts of Assyria there are occasional rains during the winter, and, in ordinary years, frequent showers in early spring.

The dependence of the present inhabitants both for pasture and for grain is on these.

There is scarcely any irrigation; and though the soil is so productive that wherever the land is cultivated, good crops are commonly obtained by means of the spring rains, while elsewhere nature at once spontaneously robes herself in verdure of the richest kind, yet no sooner does summer arrive than barrenness is spread over the scene; the crops ripen and are gathered in; "the grass withereth, the flower fadeth;" the delicate herbage of the plains shrinks back and disappears; all around turns to a uniform dull straw-color; nothing continues to live but what is coarse, dry, and sapless; and so the land, which was lately an Eden, becomes a desert.
Far different would be the aspect of the region were a due use made of that abundant water supply--actually most lavish in the summer time, owing to the melting of the snows which nature has provided in the two great Mesopotamian rivers and their tributaries.

So rapid is the fall of the two main streams in their upper course, that by channels derived from them, with the help perhaps of dams thrown across them at certain intervals, the water might be led to almost any part of the intervening country, and a supply kept up during the whole year.

Or, even without works of this magnitude, by hydraulic machines of a very simple construction, the life-giving fluid might be raised from the great streams and their affluents in sufficient quantity to maintain a broad belt on either side of the river-courses in perpetual verdure.
Anciently, we know that recourse was had to both of these systems.