and Shatt el Kar to the south, curved eastward from Babylon, and
sweeping past Nippur, flowed like the letter S towards Larsa and then
rejoined the river. It is believed to mark the course followed in the
early Sumerian period by the Euphrates river, which has moved steadily
westward many miles beyond the sites of ancient cities that were
erected on its banks. Another important canal, the Shatt el Hai,
crossed the plain from the Tigris to its sister river, which lies
lower at this point, and does not run so fast. Where the artificial
canals were constructed on higher levels than the streams which fed
them, the water was raised by contrivances known as "shaddufs"; the
buckets or skin bags were roped to a weighted beam, with the aid of
which they were swung up by workmen and emptied into the canals. It is
possible that this toilsome mode of irrigation was substituted in
favourable parts by the primitive water wheels which are used in our
own day by the inhabitants of the country who cultivate strips of land
along the river banks.

In Babylonia there are two seasons--the rainy and the dry. Rain falls
from November till March, and the plain is carpeted in spring by
patches of vivid green verdure and brilliant wild flowers. Then the
period of drought ensues; the sun rapidly burns up all vegetation, and
everywhere the eye is wearied by long stretches of brown and yellow
desert. Occasional sandstorms darken the heavens, sweeping over
sterile wastes and piling up the shapeless mounds which mark the sites
of ancient cities. Meanwhile the rivers are increasing in volume,
being fed by the melting snows at their mountain sources far to the
north. The swift Tigris, which is 1146 miles long, begins to rise
early in March and reaches its highest level in May; before the end of
June it again subsides. More sluggish in movement, the Euphrates,
which is 1780 miles long, shows signs of rising a fortnight later than