Evidence of the Muslims` eagerness to harness every available source of water power is provided by their use of tidal mills in the tenth century in the Basra area where there were mills that were operated by the ebb-tide. Tidal mills did not appear in Europe until about a century after this.
Water power was also used in Islam for other industrial purposes. In the year 751 the industry of paper-making was established in the city of Samarqand. The paper was made from linen, flax or hemp rags. Soon afterwards paper mills on the pattern of those in Samarqand were erected in Baghdad and spread until they reached Muslim Spain. The raw materials in these mills were prepared by pounding them with water-powered trip-hammers. Writing about the year 1044, al-Biruni tells us that gold ores were pulverized by this method "as is the case in Samarqand with the pounding of flax for paper". Water power was also used in the Muslim world for fulling cloth, sawing timber and processing sugarcane. It is yet to be established to what extent industrial milling in Europe was influenced by Muslim practices. A likely area of transfer is the Iberian Peninsula, where the Christians took over, in working order, many Muslim installations, including the paper mills at Jativa.
The expression `fine technology`, embraces a whole range of devices and machines, with a multiplicity of purposes: water clocks, fountains, toys and automata and astronomical instruments What they have in common is the considerable degree of engineering skill required for their manufacture, and the use of delicate mechanisms and sensitive control systems. Many of the ideas employed in the construction of ingenious devices were useful in the later development of mechanical technology.
The tradition of pre-Islamic fine technology continued uninterrupted under Islam and was developed to a higher degree of sophistication. Monumental water clocks in Syria and Mesopotamia continued to be installed in public places. The Abbasid Caliphs were interested in clocks and ingenious devices. The story of the clock that was presented by Harun al-Rashid (786-809), to Charlemagne in 807 AD is well known
The Evolution from Water to Mechanical Clocks
The technology of clock- making was transferred to Muslim Spain. About the year 1050 AD, al-Zarqali constructed a large water clock on the banks of the Tagus at Toledo in Spain. The clock was still in operation when the Christians occupied Toledo in 1085 AD.
A manuscript describing Andalusian monumental clocks was written in the eleventh century by Ibn Khalaf al-Muradi. Most of his devices were water clocks, but the first five were large automata machines that incorporated several significant features. Each of them, for example, was driven by a full-size water wheel, a method that was employed in China at the same period to drive a very large monumental water clock. The text mentions both segmental and epicyclical gears. (In segmental gears one of a pair of meshing gear-wheels has teeth on only part of its perimeter; the mechanism permits intermittent transmission of power). The illustrations clearly show gear-trains incorporating both these types of gearing. This is extremely important: we have met simple gears in mills and water-raising machines, but this is the first known case of complex gears used to transmit high torque. It is also the earliest record we have of segmental and epicyclical gears. In Europe, sophisticated gears for transmitting high torque first appeared in the astronomical clock completed by Giovanni de Dondi about AD 1365.
In a Spanish work compiled for Alfonso X in 1277 AD, in which all the chapters are translations or paraphrases of earlier Arabic works we find a description of a clock. It consisted of a large drum made of wood tightly assembled and sealed. The interior of the drum was divided into twelve compartments, with small holes between the compartments through which mercury flowed. Enough mercury was enclosed to fill just half the compartments. The drum was mounted on the same axle as a large wheel powered by a weight-drive wound around the wheel. Also on the axle was a pinion with six teeth that meshed with thirty-six oaken teeth on the rim of an astrolabe dial. The mercury drum and the pinion made a complete revolution in 4 hours and the astrolabe dial made a complete revolution in 24 hours. Clocks incorporating this principle are known to work satisfactorily, since many of them were made in Europe in the seventeenth and eighteenth centuries. This type of timepiece, however, with its effective mercury escapement, had been known in Islam since the eleventh century, at least 200 years before the first appearance of weight-driven clocks in the West.
An important aspect of Islamic fine technology is the tradition of geared astronomical instruments which were described in Arabic literature. The most notable example is the astronomical geared mechanism that was described by al-Biruni and called by him Huqq al-Qamar (Box of the Moon). From al Biruni`s text we understand that these mechanisms were known in Islamic astronomy. A surviving example is the geared calendar dated 1221/2 AD that is part of the collection of the Museum of the History of Science at Oxford.