sent 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. In
the tract between the Tigris and the Upper Zab, which is the only part
of Assyria that has been minutely examined, are distinct remains of at
least one Assyrian canal, wherein much ingenuity and hydraulic skill is
exhibited, the work being carried through the more elevated ground by
tunnelling, and the canal led for eight miles contrary to the natural
course of every stream in the district. Sluices and dams, cut sometimes
in the solid rock, regulated the supply of the fluid at different
seasons, and enabled the natives to make the most economical application
of the great fertilizer. The use of the hand-swipe was also certainly
known, since it is mentioned by Herodotus, and even represented upon the
sculptures. [PLATE XXV., Fig. 1.] Very probably other more elaborate
machines were likewise employed, unless the general prevalency of can
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