132 SYLVICULTURE IN THE TROPICS R .u 



wheels, moved by the current of the Adige, which raise 

 the water to a height of 6 or 7 metres. They are also 

 used in Egypt, and also in Mesopotamia, where they go 

 by the name of " Naoura." 



For shallow lifts the Archimedean screw is much 

 used in the Nile Delta, while for raising water from 

 deep wells the Charas is largely employed in India. 

 This consists of a large leather bag attached to a rope 

 passing over a pulley placed across the mouth of the 



well. The rope is hauled in by bullocks walking down 

 an inclined plane (Fig. 26), and the water is emptied 

 from the bag into a receiving trough by a man who 

 stands at the month of the well. In some parts of 

 India an improved Charas is made which does away 

 with the necessity of keeping a man at the mouth of 

 the well. The leather bag is made horn-shaped and has 

 two openings, one at the wider end to take in the 

 water and one at the pointed end to pour it out. Each 

 end of the bag is attached to a separate rope, and each 

 rope passes over its own pulley, that connected with the 



