ABSTRACT
For about 2,000 years water was the main source of power for milling and other industrial purposes. For about half that period, apart from the muscular energy of men and animals, it was the only source. Even today, given the right hydraulic conditions, water power can compete successfully with other sources of energy. In view of the importance of water power in the social and economic life of many communities, it is hardly surprising that a good deal of attention has been paid to the subject by historians of technology. As we shall see, the use of water power began in about the second century bc, and we might therefore expect, from this comparatively recent date, that scholars would have been able to resolve the main problems about the origins of diffusion of the various types of water-powered machines. This is not the case, partly because the evidence is very scanty for certain periods; as usual, there is very little information from the Dark Ages and any conclusions about applications of water power in those centuries are bound to be tentative. We do now have a reasonably clear picture about the development of water-based industries in medieval Europe from the eleventh century onwards, but until now very little has been published on the situation in Islam. Some historians, assuming from the lack of available information that the Muslims made only limited use of water power, have constructed theories to explain this apparent lack of interest as being due to factors inherent in Muslim society. These theories are, however, based upon a faulty premise, since it can be demonstrated that the Muslims were anything but indifferent to the benefits to be obtained from the exploitation of water power.
