(i) Uttar Pradesh, Punjab, Haryana. (ii) Ordinary wells and tube-wells. (iii) The prevailing methods are the Persian Wheel, Mhote and the Picotin. The Persian wheel: It is also known as ‘Rehat’ and is worked by bullocks, buffaloes or camels. Mhote: It is also worked by bullocks moving up a sloping ramp to pull up a big leather bucket. Picotin: In this device a vertical pole is employed for balancing the bucket and the equivalent load fixed on either ends. It is also known as ‘Dhenkuli’. (iv) Advantages: (a) easy to dig and construct, (b) cheap Disadvantages: (a) wells can irrigate a very small area about half an hectare of land. (b) In times of drought they run dry. (c) Besides there is strain on the animals.