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Isnin, 6 September 2010

Islamic Mechanical Engineering

Mechanical Engineering

Water-Raising Machines

The saqiya was widely used in the Muslim world from the earliest days onwards. It was introduced to the Iberian Peninsula by the Muslims, where it was massively exploited. Its Maximum expansion in the Valencian Country took place throughout the eighteenth century. In 1921 their number amounted to 6000 installed in the Orchards of Valencia, which supplied water to 17866 hectares. Throughout the twentieth century they have been replaced by hydraulic pumps.

A saqiva in Ma'arrat al-Nu'man near Aleppo

Today, this ancient water raising machine is seen in a few farming areas in the northern Mexican states. It also survives in the Yucatan Peninsula. It is reported that one group of farmers in Veracruz, Mexico is reverting back to using the traditional technology of the saqiya.

The na'ura (noria) is also a very significant machine in the history of engineering. It consists of a large wheel made of timber and provided with paddles. The large-scale use of norias was introduced to Spain by Syrian engineers. An installation similar to that at Hama was in operation at Toledo in the twelfth century.

The Na'ura (Noria) of Albolafia in Cordoba also known as Kulaib, which stands until now, served to elevate the water of the river until the Palace of the Caliphs. Its construction was commissioned by Abd al-Rahman I, and has been reconstructed several times.

The Noria of Cordoba

The noria was heavily exploited all over Muslim Spain. It was diffused to other parts of Europe, and, like the Saqiya, has shown remarkable powers of survival into modern times.
Five water-raising machines are described in al-Jazari's great book on machines, composed in Diyar Bakr in 1206. One of these is a water-driven saqiya, Three of the others are modifications to the shaduf. These are important for the ideas they embody, ideas which are of importance in the development of mechanical engineering as we shall mention below. The fifth machine is the most significant. This is a water-driven twin-cylinder pump. The important features embodied in this pump are the double-acting principle, the conversion of rotary into reciprocating motion, and the use of true suction pipes. The hand-driven pumps of classical and Hellenistic times had vertical cylinders which stood directly in the water which entered them through plate-valves in the bottoms of the cylinders on the suction strokes. The pumps could not, therefore, be positioned above the water level. This pump of al-Jazari could be considered as the origin of the suction pump. The assumption that Taccola (c. 1450) was the first to describe a suction pump is not substantiated. The only explanation for the sudden appearance of the suction pump in the writings of the Renaissance engineers in Europe is that the idea was inherited from Islam whose engineers were familiar with piston pumps for a long time throughout the Middle Ages.

Twin Cylinder Suction Pump of Al-Jazari

Evidence for the continuation of a tradition of mechanical engineering is provided by a book on machines written by Taqi al-Din about the year 1552. A number of machines are described, including a pump similar to al-Jazari's, but the most interesting device is a six-cylinder 'Monobloc' pump. The cylinders are bored in-line in a block of wood which stands in the water - one-way valves admit water into each cylinder on the suction stroke. The delivery pipes, each of which is also provided with a one-way clack-valve, are led out from the side of each cylinder and brought together into a single delivery outlet. It is worthy of note that Taqi al-Din's book antedates the famous book on machines written by Agostino Ramelli in 1588. It is therefore quite possible that there was some Islamic influence on European machine technology even as late as the sixteenth century as we have alluded above

More detail and information click http://www.history-science-technology.com/
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