Prof. Salim T S Al-Hassani In this pioneering survey of some of the machines of Al-Jazari and Taqi Al-Din, Professor Salim Al-Hassani uses in-depth analysis with the tools of modern technology to make them live again. Relying on the original manuscripts and applying modern engineering technology and graphic modelling with computers, we can see these machines designed and described many centuries ago come to life.
Table of contents
1. Introduction
2. Muslim Contributions to Engineering
3. Al-Jazari: A Biographical Sketch
4. Taqi Al-Din: Short Biography
5. The Working Principles of the Machines
5.1 The Reciprocating Pump of Al-Jazari
5.2 The Six Cylinder Pump of Taqi Al-Din
5.3 The Third Water Raising Machine of Al-Jazari
5.4 The Elephant Clock of Al-Jazari
6. Mathematical Analysis
7. Animations and 3D Graphics
8. Notes and References
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Note of the editor
This article is based on a paper presented by Professor Salim Al-Hassani at the 22nd Annual Conference on the History of Arabic Sciences held at Aleppo University, Aleppo, on 23-25 October 2001. It summarises the results of his investigations on the machines of Al-Jazari and Taqi Al-Din, sponsored by the Foundation for Science, Technology and Civilisation (FSTC, Manchester) and carried out at the University of Manchester, Institute of Science and Technology (UMIST –now The University of Manchester) as Final Year student projects for the award of B. Eng Hons. Degree in Mechanical Engineering.
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Figure 1: The Elephant Clock: Leaf from a manuscript of Al-Jazari's Kitab fi macrifat al-hiyal al-handasiyya (The Book of Knowledge of Ingenious Mechanical Devices) dated 715 H/1315 CE. (Source) |
The investigations recently conducted by the author of this article explore the origin and operation of some complex machines invented by two genius scientist, engineer and inventors, Al-Jazari and Taqi al-Din, in the Islamic east, between the late 12th century and late 16th century. These machines are water raising machines and water clocks. The investigation was an in-depth research and discussion, aiming at the reconstruction of these devices and the description of their operation, besides a detailed account of their components.
Geometrical and mechanical details were obtained from the original Arabic manuscripts and from English translations. Mathematical descriptions of the working (kinetic, motion and energy characteristics) were coded in MATHCAD to predict the various positions of the parts and the motion of the water. The mathematical analysis confirmed the viability and efficiency of the original design as described by Al-Jazari and Taqi Al-Din.
The original dimensions of the components were used to produce modern engineering drawings and these were used to produce images in 3D Studio Max software for each object. After assembling the objects, a full three dimensional image is produced of the machine.
The images can be rotated to produce the effects of fly over and fly around the machines. By incrementally adjusting the position, according to the machine kinematics of each component, a sequence of images was obtained to produce the effect of 3D animated motion. A CD with full interactive instructions to assist in understanding and investigating the mechanisms of the machines has been produced. For the first time, this project succeeded in combining state-of-the-art engineering and information technology to bring these machines to life.
2. Muslim Contributions to Engineering
Studies made during the past fifty years demonstrate that the scientists and engineers of the classical age of Islamic civilisation made substantial contributions to developments in engineering and that some of their accomplishments were passed on to the Europeans through Spain and Italy and the Crusades.
Many of the achievements made in engineering and technology in the Islamic world in earlier centuries are not well known. Two main reasons for this were suggested by Ludlow and Bahrani[1]:
1. During that period, several engineers and technologists were practical rather than literary people. They carried out their work competently but did not write down or publish their discoveries and achievements. Their skills and knowledge were passed on from master to pupil without being recorded. The extent of their ability and skill can now be judged from the few articles and instruments they made which still survive in museums.
2. In the few cases where the engineers and technologists did write down an account of their work and observations, some of their manuscripts have been mislaid or destroyed, while a few others are still extant and have been studied by historians of science and technology during the last decades.
During the past fifty years there has been a revival of interest in the history of technology during the early Islamic period. A few Arabic manuscripts dealing with mechanical engineering have been found and some of these were translated into European languages. Among the most important of these manuscripts are:
a. Kitab al-hiyal (Book of Ingenious Mechanical Devices) by Banu Musa, the three sons of Musa Ibn Shakir. This manuscript, which was written in Baghdad about 830 CE, describes approximately one hundred pieces of technical equipment. The book has been edited by A. Y. Al-Hassan (1981) and translated into English by Donald R. Hill (1979).
b. Kitab fi ma'rifat al-hiyal al-handasiya (The Book of Knowledge of Ingenious Mechanical Devices) by al-Jazari written in Diyar Bakr (Turkey) about 1206 CE. This book, which has recently been translated into English by Donald R Hill [2] contains descriptions and illustrations of clocks, fountains and perpetual flutes, machines for raising water and other miscellaneous devices.
c. Al-Turuq al-saniya fi al-alat al-ruhaniya (Sublime Methods in Spiritual Machines) by Taqi Al-Din ibn Ma'ruf, written in Damascus about 1551 CE. This manuscript, which has not yet been translated into English, contains descriptions and illustrations of clocks, weight lifting equipment, pumps and various other machines.
The contributions of engineering in the Islamic world are evidently many; yet the materials or treatises available to researchers are very limited, and much more effort is needed to study this field. Useful contributions have been made by Eilhard Wiedemann, Fritz Hauser, Ahmed Y. Al-Hassan and Donald R. Hill. The latter is the most important contributor to this project and most of his works focus on Al-Jazari's Kitab fi ma'rifat al-hiyal al-handasiyyah (The Book of Knowledge of Ingenious Mechanical Devices).
Quoting Dr Hill: "As far as I am aware, there has been no archaeological study of medieval Islamic technology, nor any detailed technical examination of those machines, which still exist, such as the Noria at Hamah, Syria."
Medieval Islamic technology can be divided into two categories, namely "fine technology" and "utilitarian technology". The term "fine technology" refers to machines or instruments that were designed to cause wonder and aesthetic pleasure to courtly circles, or for timekeeping, or for the use of scientists (mainly astronomers). The source of information on fine technology can be found in a few technical treatises, such as Al-Jazari's The Book of Knowledge of Ingenious Mechanical Devices.
The term "utilitarian technology" refers to machines that were essential to the economic prosperity of society but were very much simpler technically than the construction of fine technology. The source of information on utilitarian technology comes largely from archaeology finds, examination of existing machines and references in the works of geographers, travellers and other non-technical writers. Machines of this category include mills, water-raising devices and textile machinery [3].
It is interesting to note that Al-Jazari's third water-raising device incorporates both categories of technology, as the machine is designed to be a beautiful ornamental artefact with splendid craftsmanship which raises water at the same time.
3. Al-Jazari: A Biographical Sketch
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Figure 2: The reciprocating pump from Al-Jazari's manuscript. Topkapi Palace Museum Library, Ahmet III 3472 |
Al-Jazari was in the service of Nasir al-Din, the Artuqid King of Diyar Bakr, and he spent twenty-five years with this ruling family in Southern Turkey, having served the father and brother of Nasir al-Din. The Artuqids were a Turcoman dynasty who maintained a precarious autonomy during the 12th century in Mesopotamia [4]. He received patronage from the Artuqid Kings and financial means were provided through salary and pension. Therefore, he was able to devote all his time to study, research, writing and inventions [5].
Al-Jazari was quite evidently a master craftsman himself and regarded himself as one person in a succession of craftsmen and engineers [6]. He states this by describing in scrupulous detail how each device was constructed, and much of the language that he used, which involved terms common amongst the craftsmen of that time, are in use right up to the present day in the technical vocabulary of Arabic. Furthermore, he expressed awareness of the need to develop machines with a better design and greater output than the traditional ones. He did not like to copy his predecessors' work blindly. Rather, he was concerned only with innovative and ingenious designs and inventions.
Al-Jazari's main virtues were the ability to carefully manufacture and assemble components, and to devise real improvements on the work of his predecessors. He did however have a tendency to be inconsistent in his dimensions, to display some vagueness about the positioning of the equipment, and failed to give a coherent record of mathematical or geometrical processes.
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Figure 3: The six cylinder water pump from Taqi Al-Din's manuscript. |
Muhammad Ibn Ma'ruf, famous as Taqi Al-Din, was born in Damascus in 1525/6 CE, and he died in 1585 in Istanbul, the then capital of the Ottoman Empire. His full name was Taqi Al-Din Muhammad ibn Ma'ruf b. Ahmad b. Muhammad b. Yusuf b. Muhammad Al-Shami. He was the son of a judge and became a judge himself. He was described by his contemporaries as the greatest scientist and engineer on earth. He is known to have written 19 books [7]. The machines we modelled are described in his book Al-turuq al-saniyah fi al-'alat al-ruhaniyah.
Much the same observations can be made about Taqi Al-Din as those made for Al-Jazari. Nevertheless, taking drawings and text together, it can be said that they fulfilled their declared intention of describing the devices so that they could be reconstructed by their successors. Indeed, the "castle" water clock was reconstructed in the Science Museum, London, for the 1976 World of Islam Festival. It works perfectly, exactly in accordance with Al-Jazari's intention. Recently, the Frankfurt Institute of the History of Arabic and Islamic Sciences, under the direction of Fuat Sezgin, has constructed small models of a few of Al-Jazari's devices. Our present project also fulfils that aspiration in that all of Al-Jazari's machines as well as those of Taqi al-Din will be re-constructed by engineering and computer graphics.
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Figure 4: 3D image extracted from the reproduction of the reciprocating pump by scholars of FSTC. (© FSTC) |
This pump (Fig. 2) was first made by Al-Jazari in 1206. Taqi Al-Din also gave a full description of the pump. Left image (Fig. 4) shows a 3D image of this pump as produced from engineering analysis based on the details given by Al-Jazari.
The pump consists of two opposing copper cylinders, each containing a piston. The two pistons are connected through a rod, which is pin-jointed to a swinging arm pivoted at the base of the pump.
The arm is slotted so that a crank-pin on a gear wheel causes it to swing with wheel rotation. The wheel is driven by a water wheel or an animal drive. The two cylinders are connected to manifolds with inlet and outlet flap. The flaps act as non-return valves.
5.2. The Six Cylinder Pump of Taqi Al-Din
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Figure 5: 3D image of Taqi Al-Din's six cylinder water pump. © FSTC |
Taqi Al-Din explained how this pump (Fig. 3) works in his manuscript. The input power source is the river and the resultant output is the water head delivered. The river exerts a force on the scoops which provide the drag force causing the wheel and camshaft to rotate. With the rotation of the camshaft, each cam pushes its connecting rod downwards. The connecting rods are pivoted at the centre. The distal end of the connecting rod lifts the lead weight upwards. As the lead weight moves upwards, it pulls the piston with it, creating vacuum which sucks the water through a non-return clack valve into the piston cylinder. After the camshaft rotates to a certain angle, the cam releases the connecting rod. This marks the point where the piston's stroke ends. Then, the lead weight pushes the piston under gravity forcing against the clack valve. As described earlier, the clack valve closes when the water moves in this direction, so that the water is forced to go through the other hole and through the delivery pipes. The synchronisation and control sequence of all the pistons is provided by the angular arrangement of the cams around the shaft.
5.3. The Third Water Raising Machine of Al-Jazari
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Figure 6: The third water raising machine from Al-Jazari's manuscript. |
This machine on the left (Fig. 6) was described in full by Al-Jazari. The image below (Fig. 7) shows a 3D image of this machine.
Water flows through the inlet pipe into the basin and out on to the scoops turning the water turbine.
The rotation is transferred through the cogwheel (gear A) and the lantern (pinion gear B).
The rotation is then transmitted via a pillar connected to the upper lantern and the cogwheel which turns the sindi-wheel.
The sindi-wheel carries a series of jars connected to ropes. As the jars dip in and out of the water basin, they carry water up to the aqueduct.
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Figure 7: 3D image of Al-Jazari's third water raising machine.© FSTC |
5.4. The Elephant Clock of Al-Jazari
The first image (Fig. 8A) below shows a sketch of the elephant clock by Al-Jazari. The second image (Fig. 8B) shows a schematic drawing of the clock as given in Ludlow and Bahrani 1978. Fig. 9 shows a 3D image of the various components of the clock. The elephant clock is a fine example of the many exquisite devices created during the Muslim Golden Age. It is classified as fine technology, as the device is used either for amusement and aesthetic pleasure or for astronomical observation and computation. It is described as one of the most spectacular clocks invented by Al-Jazari and it is estimated to be about 4 feet long and 6 feet high. It also demonstrates his considerable skill in both design and construction. The characteristics of the elephant clock consist of several mechanisms that are presently used in modern engineering such as automata, flow regulators and a closed-loop system.
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Figure 8A: The Elephant Clock: Leaf from a manuscript of Al-Jazari's Kitab fi macrifat al-hiyal al-handasiyya (The Book of Knowledge of Ingenious Mechanical Devices) dated 715 H/1315 CE. (Source). 8B: Schematic drawing of the elephant clock. |
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Automata: The clock employed automata, such as the striking of the cymbal and chirping of the bird, to mark the passage of the hours.
Flow Regulators: A small orifice in the submersible float is carefully calibrated to produce correct rates of flow under various heads of water rates. This rate of flow determines the time at which the clock strikes at hourly interval; it is set by trial and error methods.
Closed-loop system: The clock will continue to work as long as there are metal balls in the magazine.
Gravitational Force: The clock employs gravitational force as motive power. A submersible float or tarjahar drives it (a tarjahar is a device used for timing the allocation of irrigation water to farmers). The steady sinking of the float acts as gravitational force, pulling the wire that activates the tripping mechanism. In addition, as the ball drops onto the serpent's mouth (during operation), it activates a gravitational force, thus pulling down the serpent's head. As the ball leaves the serpent's mouth, it activates a return mechanism.
Return Mechanism: The serpent has a return mechanism in the form of a pulley. When the return mechanism is activated, the lowered serpent's head returns to its original position and lifts a chain along with it. This chain is connected to the float and it lifts up the submersible float and empties its content, the submersible float is now on the surface again and the cycle repeats.
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Figure 9: The Mahout on the neck of the elephant, the vases on either side and the scribe on top of the circular platform. |
Control Mechanisms: The submersible float or tarjahar drives the clock. Initially, the submersible float lies on the surface of the water in the tank. A calibrated orifice on its underside allows water to enter and subsequently sinks the float. Attached to the submersible float are a wire and a chain. The wire runs from the float to the ball release mechanism inside the castle and activates it when the float sinks. The chain runs from the underside of the float to a staple on the tail of the serpent. Upon activation of the return mechanics for the serpent, the chain will tilt the sunken float out of the water, thus emptying it of its contents.
Then the emptied float will rest on the water surface and repeat the cycle. At the top of the clock, supported by four columns, is the castle (a square brass box with a detachable dome). Inside the castle is a ball release mechanism, which when activated, releases a ball that travels down a channel leading to the beak of the falcon. The ball will travel from the beak of the falcon onto the open mouth of the serpent. The serpent is in effect a pulley which rotates on an axle that rests on bearings fixed between each pair of the columns. Upon loading with the ball, the serpent head will be lowered down to the vase. Once the ball drops away from the serpent's mouth, the return mechanism of the serpent is activated and the serpent returns to its original position.
Full mathematical analyses of each machine are contained in the respective project reports placed in the Department of Mechanical Engineering, UMIST, in May 2001. It is beyond the scope of this paper to describe these analyses. MATHCAD was used to link all the equations describing the motion of each component. The dimensions were obtained from Al-Jazari's and Taqi Al-Din's manuscripts. On a number of occasions, we had to make a best guess of the actual dimensions of the component.
Essentially, each analysis starts with equating the forces acting on each component allowing for friction as well as compatibility of velocities and displacements and the output is predicted. For example, in the case of Taqi Al-Din's six cylinder pump, the analysis starts with equating the weight of the lead and pistons to the required water head through the collective output pipe. The lead weights are then balanced by the force on the connecting rods which determine the torque on the camshaft which then fixes the force required by the water flow from the river. Allowance had to be made for friction forces at the pivot and for all sliding surfaces. Further allowances are made for the shape of the scoop at the end of each spoke of the water wheel.
When all the equations are encoded into MATHCAD, the solution provides the relationship between the geometrical and mechanical parameters and graphs are plotted to assist in the assessment of the efficiency of the machine. Additional analysis was conducted on the strength requirement of the components. From the forces and torques, stresses were calculated which are compared to the failure strengths and buckling capacity of the components.
Modelling and animation were carried out using 3D Studio MAX R3.1 package, based on the findings on the research and mathematical analysis of the machines. 3D Studio MAX is a very powerful graphics software used for modelling, animating, image processing and texture mapping for both 2D and 3D objects. Modelling the machines was done in four steps:
1. Creating objects and setting them into positions;
2. Modifying some objects to match those in the real machine;
3. Assigning materials to objects to make them look realistic;
4. Creating lights and cameras and setting them into proper positions to give a real look to the model.
The graphics show the components, devices and machines in different angles of views, close up views and "wire frame" views. The different angles of views include the front perspective view, rear perspective view, front view and left view. The close-up view zooms onto the chambers of the device in perspective view, while the "wire frame" view shows the "skeleton" view of the devices. The 3D animations consist of two movie files: a 360º rotational view and one that shows the movements of individual components during their operations. These animations enable the reader to view the device from different angles and also to view the device in operational mode. The 3D drawing file and animations are stored on CDs to enable a step-by-step construction of the machines or modification of the drawings.
[1.] C. G. Ludlow and A. S. Bahrani, 1978, "Mechanical Engineering during the Early Islamic Period", I. Mech. E, The Chartered Mechanical Engineer, pp. 79-83.
[2.] Ibn Al-Razzaz al-Jazari, 1974, The Book of Knowledge of Ingenious Mechanical Devices, translated and annotated by Donald R Hill. Dordrecht: D. Reidel.
[3.] Dionisius A. Agius and Richard Hitchcock (Editors), 1994, The Arab Influence in Medieval Europe. New York: Ithaca Press, p. 25.
[4.] Donald R. Hill, 1998, Studies in Medieval Islamic Technology, Edited by David A. King. London: Ashgate, Variorum collected studies series, p. 253.
[5.] Ahmad Y. Al-Hassan and Donald R. Hill, 1986, Islamic Technology: An Illustrated History. Cambridge University Press, p. 12.
[6.] Compilation of writers, 1976, The Genius of Arab Civilisation (Source of Renaissance), Edited by John R Hayes. Oxford: Phaidon, p. 177.
[7.] For details on his bio-bibliography, see the book by Ahmad Y. Al-Hassan, Taqi Al-Din wa-'l-handasah al-mikanikiyah al-'arabiyah (Taqi Al-Din and the Arabic mechanical engineering) with "Kitab al-turuq al-saniyah fi al-alat al-ruhaniyah" from the sixteenth century (Aleppo, 1976).
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