MESOPOTAMIA Mesopotamia, which belongs to the basins of the Tigris and Euphrates, lies between the Syrian desert and the hill country bordering the Iranian plateau. The land has a gradual slope from the north-west as fax as an old coast line, which runs from Hit on the Euphrates towards Samara on the Tigris, and beyond which stretches a level plain that is really the delta of these great rivers. The scanty rainfall occurs during the winter months, and at Bagdad probably does not exceed 5 inches, though to the east of the Tigris it is over 10 inches. The winters are warm and the summers hot : at Bagdad the range is from 45° F. in January to 87° F. in August. In the north, and in the vicinity of the rivers as far south as the latitude of Bagdad, there are considerable areas of grazing land, but much of the true " Mesopotamia " is desert. In the delta, past civilisations have maintained themselves by the aid of great systems of irrigation which have fallen into decay ; and, even with the primitive methods at present adopted, crops of wheat, millet, and sesame are grown, while barley is often cultivated with winter rainfall only. In the more southerly parts of the delta, where the land is inundated yearly, population is densest, and the cultivation of the date-palm has given to its people a more settled character than is the case in other parts of the country. The proposed scheme for the restoration of the irriga tion system in the delta is 'of considerable interest. As the
rivers are in flood during the spring when the highland snow is melting, and as the summers are hot and dry, the basin system of ancient Egypt is impossible, and perennial irrigation is necessary. The total area of the delta is about 5,000,000 hectares ; and Sir William Willcocks estimates that the available water supply is sufficient to irrigate 3,000,000 hectares of winter crops (wheat, barley, beans, and roots, which require irrigation from November to May), and 1,250,000 hectares of summer crops (millet, sesame, and cotton, which need water from April till the middle of July). At present, a beginning has been made to works, which, if they are eventually completed as proposed, will bring 1,400,000 hectares under irrigation.
The principal towns of Mesopotamia are Basra, at the head of navigation for ocean-going ships on the Shat-el-Arab, and the chief port of the country ; Bagdad, which is reached by river steamers from Basra, and carries on an important trade with Persia ; and Mosul, which is the centre of the pastoral area in the north of the country. The principal exports include dates, wool, barley, and opium ; while cotton goods and other textiles, sugar, and timber form the greater part of the imports.