IRRIGATION. 15 



already utilized land fringing the river banks. The writer followed 

 up one of the main canals and reached the end of the irrigation ditches 

 to find, on the very border of the desert, luxuriant patches of alfalfa 

 and tine looking* 1< >-year-old date palms. (See PI. I. tig. 3.) The Arabs 

 are gradually, but very slowly, lengthening the canals and watering 

 more desert eA'erv year. A great impetus was given to date culture 

 in Mesopotamia by the opening of the Suez Canal in 1869. This 

 brought the European and American markets within easy reach by 

 water, and enabled the growers to get their dates to London and New 

 York in time for the autumn market, avoiding the expense and delays 

 of their transportation by camel across the desert. Large areas of 

 palms which were planted at that time are now in the prime of their 

 produeth'eness. 



The method of planting is determined by the irrigating ditches, 

 which are large (often 3 feet by 3 feet) and cut the ground up into 

 small rectangular peninsulas, 10 to 15 by 2<> to 30 feet in size. (PL I, 

 tig. "2. and PL II. tig. 2.) On each peninsula *2. or sometimes 3, palms 

 arc set. (PL VII. tig. 1.) Often the peninsulas are much larger and 

 hold from 1 to 5 and even as high as 10 palms. The size of these 

 peninsulas depends somewhat upon the permeability of the soil and 

 the height to which the irrigation water rises in the ditches. On an 

 average 100 palms are planted to a "djerib." which unit of measure is a 

 trifle less than an acre. In order to prevent the waters receding too 

 quickly from the canals when the tide falls, dams of mud are built, 

 and pipes, or the hollow trunks of palms, are run through them, which 

 permit the water forced into the canals by the rising tide to flow away 

 slowly. The length of time during which the canals are filled with 

 water is more or less under the control of the proprietor, and as the 

 supply is practically unlimited no tax of any kind is paid nor is any regu- 

 lation necessarv regarding its use. In short, the Bassorah date grower 

 has only to see that his ditches are kept in order, which is an easy 

 matter where the soil is as pure adobe as the clay of a brickyard and 

 the backwater of the river will till and empty them twice every twent} T - 

 four hours. The conditions of this form of irrigation, which might 

 be called a tidal one. are quite ideal and so far as known are found 

 on Mich a scale nowhere else in the world. Professor Hilgard, of the 

 California Experiment Station, says that the waters of the Sacramento 

 River are being utilized in a similar way, but on no such scale. With 

 the proper extension of the canals on both sides of the river an area 

 covering several million acres could, it is believed, be planted to dates 

 and the Bassorah region might then supply the dates of the world. 



Conditions in Bagdad are quite different. The banks of the Tigris 

 are high, often 20 feet or more, and even at its highest level the water 

 never flows into the irrigating canals, but must be lifted laboriously 

 by means of contrivances of Babylonian antiquity, called ' thirds. " 



