Photograph showing a bullock-driven irrigation wheel drawing water from the Indus, taken by unknown photographer in the Sindh province now in Pakistan, c.1900, from an album of 46 prints titled 'Karachi Views'. The Persian water wheel is a traditional water-lifting device in South Asia. Water wheels were invented in ancient Egypt and Persia as an improvement on well irrigation, to increase the acreage of land irrigated. In its oldest and simplest form the water wheel (saqiya or noria)consists of a number of earthen pots attached to ropes or chains and suspended round a huge wooden wheel. The wheel is at one end of a horizontal wooden axle and is connected to a small wheel at the other end. The horizontal axle is usually embedded in the ground or under a platform so that it does not interfere with the movement of draft animals. Another large wheel is mounted on a vertical axle to which is attached a long shaft. This wheel can be turned by camels, donkeys, bullocks or oxen by means of the shaft. As it turns, the small wheel on the horizontal axle is driven like a gear and in turn causes the huge wheel to rotate. The pots fill as they drop into the water and spill their water into a trough that feeds the channels which water the fields.