Changes

从地下打水最简易、廉价的的方法仍然是运用绳子和水桶在宽浅的井中提水。这类井最深能达100米，虽然少有超过45米深的。绳桶提水装置可以由人力或畜力驱动。人力绳桶装置通常每分钟能从10-15米深处提出10-15升水，而畜力装置每分钟能从15米深处提出150升水。在畜力驱动的绳桶提水装置中，系在桶上的绳子穿过滑轮固定在动物身上。为了将水提起，动物会从一个5-10度的斜土坡上往下赶。

The rope and bucket lifter can also be adapted to include two buckets which are raised and lowered alternately. In this case the pulling animal moves in a circular path and with the help of central rotating lever, rope and pulley arrangement the buckets move up and down. Each bucket has a carrying capacity of up to 70 litres. The buckets have a hinged flap at the bottom, which acts as a valve. Guide rods are provided in the well to control the movement of the buckets. The buckets are automatically filled and emptied during operation. This device can lift about 230 litres /min from depths of up to 5 metres.