178 EGYPTIAN AGRICULTURE. 



angle of 45 the wheel carries the water to a greater height 

 and discharges it more rapidly with less spilling. 



The taboot is best for lifts of 1 to 2 metres. It is 

 assumed to have a discharge of 30 cubic metres per hour, 

 but it varies much according to lift. It costs from L.E. 5 

 for a small lift, if not built in masonry, to L.E. 20 and 

 more for larger sizes placed in masonry wells. It suits the 

 country well, its main faults being rough construction and 

 frequent need for repair. The great rough cog wheels 

 with large wooden teeth of 5 -inch pitch are often 

 ridiculed but the transmission of one bullock power at 

 very slow speed requires theoretically wide-pitched te(,th, 

 and the practice of the village carpenter has sound scientific 

 basis. He has a regular scale for altering the number of 

 teeth according to the diameter of the wheel and 

 consequently the work to be done. 



Archimedean /Screw. This may be the small wooden 

 barrel 2*5 m. long x 0*40 m. diameter which a man car- 

 ries to the field on his shoulder and begins to work with 

 the preliminary of driving a post into the water to receive 

 the lower thrust end, and another post at a higher level 

 to serve as the upper bearing. Such a screw costs P.T. 60, 

 will lift water 0*75 metre, and is often used to supply a 

 sakieh when water in a canal falls just below its reach. 

 Sometimes two or three screws are used, one above the 

 other. Worked vigorously by 2 boys they will do nearly 

 as much as a sakieh. These small wooden screws have 

 a double spiral in the centre. 



An improved screw, " Tambour, Yanni," has been intro- 



