[ '*> ] 



discharges its water, the other goes down, the entrance of 

 water into the empty don being facilitated by means of a 



FIG. 44. THE BALDEO BALTI. 



valve. The arrangement of the strings to which the two 

 dons are tied after passing over three pulleys, can be best 

 understood from the above diagram (Fig. 44.) 



231. Artesian Wells. The question of sinking artesian 



FIG. 45. NUBIAN TUBE-WELL. 

 wells and tube-wells (Fig. 45) both for irrigation and drinking 



