IV. Al-Jazari's Third Water-Raising Device
Previous | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Next 1. A Revolutionary Idea There was obviously a demand from al-Jazari's masters for devices that would provide amusement and aesthetic pleasure, but it is also highly likely that his responsibilities included the design and construction of public works. In this capacity, he would have appreciated the need for improving the efficiency of water-raising methods, and have attempted to devise means to this end. Apart from their potential as practical machines, his designs have the added significance of incorporating techniques and components that are of importance in the development of Islamic technology [1]. Therefore, al-Jazari tinkered with the idea of a fanciful water-raising device, which pictured a fake ox that appeared to provide a wheel with motive force but was in fact supplied by a hidden current of waterpower driving a water turbine [2].  | | Large image | Figure 8: Another depiction of al-Jazari's pump for raising water in a manuscript of copy held in Topkapi Sarayi Libray in Istanbul. (Source). |
2. Description of the Device [3] The Third Water-Raising Device was intended as a decorative attraction near an ornamental lake [4], with an element of mystification about it. Thence an ornamental lake erects an elegant open structure, with only its automata working parts visible to spectators, thus leaving the spectators curious on how the device is powered (see Fig. 8). Consider the nature of al-Jazari's working environment, it is most likely erected in the King's garden, where it caused wonder and aesthetic pleasure to courtly circles and raised water for irrigation to the garden at the same time. It was however, simply an elegant development of a utilitarian device that was used for supplying water for irrigation and domestic purposes. A development of the Saqiya, having the main difference of the device being powered by waterpower instead of animal power. The structure itself is quite small, being divided into 2 sections; the lower chamber whereby the water driven mechanism is ‘hidden' under the ground and upper chamber whereby the automated mechanism above the pool was made visible. It consists of a copper pool with an escapement, whereby water flows into the lower chamber and drives the Scoop-Wheel. The rotating Scoop-Wheel in turn rotates the Cogwheel and Lantern Pinion gears, driving the vertical hollow copper pillar with an iron stanchion beneath it. The rotating pillar in turn rotates the second set of gears in the upper chamber, driving the Sindi Wheel that raises water to the head tank (this is seen in Fig 8 and in the reconstructed depiction in Fig. 9) [5].  | | Large image | Figure 9: A 3D graphic showing the flow of water when the device is working. |
Initially, it has been thought that this device was simply an unrealistic idea of al-Jazari, whereas in fact, the Third Water-Raising Device is a scaled down version of a utilitarian machine [6]. A similar large-scale version of this machine can be located on the River Yazid in Damascus, on a riverside path called the ‘Land of the Norias' (because of the number of Norias and mills that used to line it) (see Fig. 10 and 11). The working principles are the same, however the mechanisms are orientated differently and some of the mechanisms are made differently; for example, the Scoop-Wheel is replaced by a Undershot-Wheel, the potgarland is made of chains and metal buckets.  |  | | Large image | Large image | Figure 10: Restored paddle wheels driven device on the river Yazid, Damascus, dating from the 13th century CE. It is very similar to al-Jazari's Third Water-Raising Device. | Figure 11: This drawing is based on the working principles of al-Jazari's Third Water-Raising Device. |
3. Possible Problems Encountered One serious mechanical problem is the possibility of slippage of the ropes and earthenware pots, around the axle of the Sindi Wheel [7]. This could result in reduced overall efficiency as it takes longer time for the earthenware pots to reach the top and pour its content into the head tank. A solution would be to reduce the weight of the water being lifted at any one time, in relation to the total weight of the rope and earthenware pots. However, this would also result in reduced overall efficiency. However, a better solution would be the use of a set of headless nails, driven into the axle at the appropriate spacing [8], that will support the base of the pots as it travels around the axle of the Sindi Wheel, thus preventing slippage. The other problems faced would be the high cost of installing and running such machinery, the small output that would only irrigate a small area. Lastly, justifications of the need to raise a comparatively small amount of water from a running stream to a high head. The best solution would be that the King who wanted a fanciful water-raising device commissioned the device so as to cause wonder and aesthetic pleasure to courtly circles. End Notes [1] D. R. Hill, Islamic Science and Engineering, op. cit., p. 97. [2] Thomas F. Glick, Islamic And Christian Spain in The Early Middle Ages. Princeton: Princeton University Press, 1979, p. 238. [3] For al-Jazari's detailed description on the design, working principle and materials used for this device, see Appendix 9. [4] J. R. Hayes (editor), The Genius of Arab Civilization Source of Renaissance, op. cit., p. 182. [5] More details of the working of al-Jazari's machine are given in Appendix 10. [6] D. R. Hill, A History of Engineering in Classical and Medieval Times, op. cit., p. 148. [7] See Chapter V, section 3: Sindi Wheel. [8] J. G. Landels, Engineering in the Ancient World. London: Chatto and Windus, 1980, pp. 71-72. Previous | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Next
by: Salim T. S. Al-Hassani and Colin Ong Pang Kiat, Thu 24 April, 2008
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