41 



is approximately 2i gallons, or one-third of a cubic foot. The counter- 

 weight is generally a piece of sun-dried Nile mud held together with 

 straw, cornstalks, or sugar-cane leaves. The woodwork is generall}^ 

 rough and the whole structure shows a lack of neatness. The operator 

 throws his weight on the sweep, the bucket tills, and the counterweight 

 raises it to the channel into which it is to be poured. The ground 

 where the water falls is protected from erosion l)v a mattino- of veoe- 

 table liber. A single shaduf can lift water onl}- .5 or tj feet, but it is the 

 custom to install them in series of three or four, which work together, 

 raising the water from 20 to 30 feet. A number of shadufs so oper- 

 ated need not necessarilj' be in a line. It is quite conunon to find the 

 lower shaduf 50 or even 100 feet up or down stream from the others, 

 but it is better to get them as close together as possible, to reduce the 

 loss by seepage. 



A shaduf operated b}^ one person can raise about 3 cubic feet of 

 water per minute. A man usuall}^ works two hours at a time, and 

 two men relieving each other put in about ten hours a day. Thej^ 

 can, therefore, with one machine, raise 1,800 cubic feet of water per 

 day. Assuming that at each irrigation the land is covered to a depth 

 of 1 inch, a device of this kind would irrigate al)out half an acre a da}'. 

 The following table shows the efficiency of a number of shadufs on 

 which data were obtained: 



Efficiencij of tin' shaduf us d ii:aii;r-r<miny device. 



THE SAKIYEH. 



The sakiyeh is as common as the shaduf. It is estimated that there 

 are 12,000 of them in that part of the delta between the branches of 

 the Nile. There are probably 50,000 altogether in Egypt. The 

 machine is con.structed as follows: A horizontal wooden wheel aljout 

 10 feet in diameter, furnished with cogs projecting about 8 inches from 

 its circumference, is supported on a vertical shaft, the lower end of 



