Ismail al-Jazari
Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī was a polymath: a scholar, inventor, mechanical engineer, artisan and artist from the Artuqid Dynasty of Jazira in Mesopotamia. He is best known for writing The Book of Knowledge of Ingenious Mechanical Devices in 1206, where he described 50 mechanical devices, along with instructions on how to construct them. One of his more famous inventions is the elephant clock. He has been described as the "father of robotics" and modern day engineering.
Biography
Al-Jazari was born in the area of Upper Mesopotamia in 1136. Sources state his exact location is unknown, but they speculate he could have been born in Jazirat ibn Umar, where he got the name Jazari from or Al-Jazira which was used to denote Upper Mesopotamia. The only biographical information known about him is contained in his Book of Knowledge of Ingenious Mechanical Devices. Like his father before him, he served as chief engineer at the Artuklu Palace, the residence of the Mardin branch of the Artuqids which ruled across Upper Mesopotamia as vassals of the Zengid dynasty of Mosul and later of Ayyubid general Saladin. Little is known about his ethnic background, so he has been variously described as Arab, Kurdish or Persian.Al-Jazari was part of a tradition of artisans and was thus more a practical engineer than an inventor who appears to have been "more interested in the craftsmanship necessary to construct the devices than in the technology which lay behind them" and his machines were usually "assembled by trial and error rather than by theoretical calculation". His Book of Knowledge of Ingenious Mechanical Devices appears to have been quite popular as it appears in a large number of manuscript copies, and as he explains repeatedly, he only describes devices he has built himself. According to Mayr, the book's style resembles that of a modern "do-it-yourself" book.
Some of his devices were inspired by earlier devices, such as one of his monumental water clocks, which was based on that of a Pseudo-Archimedes. He also cites the influence of the Banū Mūsā brothers for his fountains, al-Saghani for the design of a candle clock, and Hibatullah ibn al-Husayn for musical automata. Al-Jazari goes on to describe the improvements he made to the work of his predecessors, and describes a number of devices, techniques and components that are original innovations which do not appear in the works by his precessors.
1206 edition (Ahmet III 3472)
The Artuqid ruler Nasr al-Din Mahmud is known to have commissioned the first edition of Al-Jāmi' fī ṣinā'at al-ḥiyal of Ibn al-Razzaz al-Jazari, in April 1206 at the Artuqid court. This manuscript is known as Ahmet III 3472, now in the Topkapı Sarayı Library. The miniatures are thought to reflect various aspects of the Artuqid court at the time. Ibn al-Razzaz al-Jazari was employed at the Artuqid court during the last quarter of the 12th century, and this is the earliest known manuscript of his opus.Mechanisms and methods
The most significant aspect of al-Jazari's machines are the mechanisms, components, ideas, methods, and design features which they employ.Camshaft
A camshaft, a shaft to which cams are attached, was described in 1206 by al-Jazari, who employed them in his automata, water clocks and water-raising machines.Crankshaft and crank-slider mechanism
The eccentrically mounted handle of the rotary quern-stone in fifth century BCE Spain that spread across the Roman Empire constitutes a crank. The earliest evidence of a crank and connecting rod mechanism dates to the 3rd century AD Hierapolis sawmill in the Roman Empire. The crank also appears in the mid-9th century in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices.In 1206, al-Jazari invented an early crankshaft, which he incorporated with a crank-connecting rod mechanism in his twin-cylinder pump. Like the modern crankshaft, al-Jazari's mechanism consisted of a wheel setting several crankpins into motion, with the wheel's motion being circular and the pins moving back-and-forth in a straight line. The crankshaft described by al-Jazari transforms continuous rotary motion into a linear reciprocating motion, and is central to modern machinery such as the steam engine, internal combustion engine and automatic controls.
He used the crankshaft with a connecting rod in two of his water-raising machines: the [|crank-driven saqiya chain pump] and the [|double-action reciprocating piston suction pump]. His water pump also employed the first known crank-slider mechanism.
Design and construction methods
English technology historian Donald Hill writes:Escapement mechanism in a rotating wheel
Al-Jazari invented a method for controlling the speed of rotation of a wheel using an escapement mechanism.Mechanical controls
According to Donald Hill, al-Jazari described several early mechanical controls, including "a large metal door, a combination lock and a lock with four bolts".Conical valve and segmental gear
A segmental gear is "a piece for receiving or communicating reciprocating motion from or to a cogwheel, consisting of a sector of a circular gear, or ring, having cogs on the periphery, or face." Lynn Townsend White wrote:Water-raising machines
Al-Jazari invented five machines for raising water, as well as watermills and water wheels with cams on their axle used to operate automata, in the 12th and 13th centuries, and described them in 1206. It was in these water-raising machines that he introduced his most important ideas and components.Saqiya chain pumps
The first known use of a crankshaft in a chain pump was in one of al-Jazari's saqiya machines. The concept of minimizing intermittent working is also first implied in one of al-Jazari's saqiya chain pumps, which was for the purpose of maximising the efficiency of the saqiya chain pump. Al-Jazari also constructed a water-raising saqiya chain pump which was run by hydropower rather than manual labour, though the Chinese were also using hydropower for chain pumps prior to him. Saqiya machines like the ones he described have been supplying water in Damascus since the 13th century up until modern times, and were in everyday use throughout the medieval Islamic world.Interestingly, the depiction of the chain in al-Jazari's pump appears to be in the form of a Möbius strip, from long before the Möbius strip was first identified as an object of study in mathematics.
Double-action suction pump with valves and reciprocating piston motion
Al-Jazari described suction pipes, suction pump, double-action pump, and made early uses of valves and a crankshaft-connecting rod mechanism, when he developed a twin-cylinder reciprocating piston suction pump. This pump is driven by a water wheel, which drives, through a system of gears, an oscillating slot-rod to which the rods of two pistons are attached. The pistons work in horizontally opposed cylinders, each provided with valve-operated suction and delivery pipes. The delivery pipes are joined above the centre of the machine to form a single outlet into the irrigation system. This water-raising machine had a direct significance for the development of modern engineering. This pump is remarkable for three reasons:- The first known use of a true suction pipe in a pump.
- The first application of the double-acting principle.
- The conversion of rotary to reciprocating motion via the crank-connecting rod mechanism.
Al-Jazari cited the Byzantine siphon used for discharging Greek fire as an inspiration for his pump. According to Donald Hill, al-Jazari's pump can be considered "a direct ancestor of the steam engine combination". According to Joseph Needham, al-Jazari's slot-rod force pump is one of "the two machines of the Middle Ages which lie most directly in the line of ancestry of the steam-engine and the locomotive" along with Wang Zhen's blowing engine a century later.
Single-bucket and four-bucket water lifting machines
Al-Jazari described single-bucket and four-bucket water lifting machines. The single-bucket version employs differentials, semi-circular gear units, bucket elevators, and gearboxes, while the four-bucket version adds a mechanical timer.Water supply system
Al-Jazari developed the earliest water supply system to be driven by gears and hydropower, which was built in 13th century Damascus to supply water to its mosques and Bimaristan hospitals. The system had water from a lake turn a scoop-wheel and a system of gears which transported jars of water up to a water channel that led to mosques and hospitals in the city.Automata
Al-Jazari built automated moving peacocks driven by hydropower. He also created automatic doors as part of one of his elaborate water clocks, and invented water wheels with cams on their axle used to operate automata. According to Encyclopædia Britannica, the Italian Renaissance inventor Leonardo da Vinci may have been influenced by the classic automata of al-Jazari.Mark E. Rosheim summarizes the advances in robotics made by Muslim engineers, especially al-Jazari, as follows:
Drink-serving waitress
One of al-Jazari's humanoid automata was a waitress that could serve water, tea or drinks. The drink was stored in a tank with a reservoir from where the drink drips into a bucket and, after seven minutes, into a cup, after which the waitress appears out of an automatic door serving the drink.Hand-washing automaton with flush mechanism
Al-Jazari invented a hand washing automaton incorporating a flush mechanism now used in modern flush toilets. This device is another example of humanoid automata. It consisted of a human figure, made from jointed copper, holding a pitcher resembling a peacock in its right hand. The pitcher was made from brass and held within it a chamber, divided into two parts by a metal plate. This mechanism aided the pouring of the water from the spout so that it was smooth and would not splutter. The reservoir in which the water was held was situated within the right-hand side of the human figure. An axle was fitted into the right elbow of the human figure so as to allow the liquid to pour from the reservoir through the spout of the pitcher. The left arm of the figure had a fixed weight which would raise and lower the arm which would hold a towel, comb and mirror.This automaton was designed to aid the king whilst he performed his ritual ablutions. A servant of the king would carry the figure and place it next to a basin that could hold liquid. The servant then turned a knob on the back of the figure which opened a valve resulting in the pouring of water from the right hand of the figure into the basin. When the reservoir was nearly empty and most of the water had been poured, a mechanism was prompted and the left hand of the figure, holding the towel, comb and mirror, was extended out in the direction of the king so that he could dry himself and tend to his beard.