Ismail al-Jazari

Abū al-'Iz Ibn Ismā'īl ibn al-Razāz al-Jazarī (1136-1206) (Arabic: أَبُو اَلْعِزِ بْنُ إسْماعِيلِ بْنُ الرِّزاز الجزري) was an important Arab Muslim scholar, artist, astronomer, inventor and mechanical engineer from al-Jazira, Mesopotamia who flourished during the Islamic Golden Age (Middle Ages).

Biography

Al-Jazari was named after the area in which he was born, al-Jazira - the traditional Arabic name for what was northern Mesopotamia and what is now northern Iraq and northeastern Syria, between the Tigris and the Euphrates. Like his father before him, he served as chief engineer at the Artuklu Palace, the residence of the Diyarbakır branch of the Turkish Artuqid dynasty which ruled across eastern Anatolia as vassals of the Kurdish general Saladin.

Al-Jazari documented fifty mechanical inventions in six different categories (along with construction drawings) in The Book of Knowledge of Ingenious Mechanical Devices (اَلجامع بَيْنْ اَلْعِلْمِ وَالْعَمَلِ اَلنَّافِعْ فِي صِناعَةُ الْحِيَلْ al-Jami Bain al-Ilm Wal-Amal al-Nafi Fi Sinat'at al-Hiyal in Arabic), published in 1206. These included the crank mechanism, connecting rod, programmable automaton, humanoid robot, reciprocating piston engine, suction pipe, suction pump, double-action pump, valve, combination lock, cam, camshaft, segmental gear, the first mechanical clocks driven by water and weights, and especially the crankshaft, which is considered the most important mechanical invention in history after the wheel. Other devices and methods he first described include hand washing devices (including Wudu machines), accurate calibration of orifices, lamination of timber to reduce warping, static balancing of wheels, use of paper models to establish a design, and casting of metals in closed mould boxes with green sand. He also described the most sophisticated water-raising machines and water clocks of his time (one of his famous clocks was reconstructed successfully at the London Science Museum in 1976).

Donald Routledge Hill wrote in the Studies in Medieval Islamic Technology:

"It is impossible to over-emphasize the importance of Al-Jazari's work in the history of engineering. Until modern times there is no other document from any cultural area that provides a comparable wealth of instructions for the design, manufacture and assembly of machines… Al-Jazari did not only assimilate the techniques of his non-Arab and Arab predecessors, he was also creative. He added several mechanical and hydraulic devices. The impact of these inventions can be seen in the later designing of steam engines and internal combustion engines, paving the way for automatic control and other modern machinery. The impact of Al-Jazari's inventions is still felt in modern contemporary mechanical engineering."

Due to his fundamental mechanical inventions, al-Jazari has been described as the "father of modern day engineering", and due to his invention of an early programmable humanoid robot, he has been hailed as the "father of robotics". Al-Jazari is considered just as important an inventor as Leonardo da Vinci.

Miniature paintings

Alongside his accomplishments as an inventor and engineer, al-Jazari was also an accomplished artist. In The Book of Knowledge of Ingenious Mechanical Devices, he gave detailed instructions for all of his inventions and illustrated them using miniature paintings to make it possible for a reader to reconstruct his inventions.

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  Diagram of a hydropowered water-raising machine from The Book of Knowledge of Ingenious Mechanical Devices by al-Jazari.
• The valve-operated reciprocating suction piston pump water-raising machine with a crankshaft-connecting rod mechanism invented by al-Jazari.
  The valve-operated reciprocating suction piston pump water-raising machine with a crankshaft-connecting rod mechanism invented by al-Jazari.
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  The elephant clock from al-Jazari's manuscript.
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  Al-Jazari's early programmable humanoid robots.

Mechanisms and components

The most significant aspect of al-Jazari's machines are the inventive mechanisms, components, ideas and design features which they employ.

Crankshaft and connecting rod mechanism

Al-Jazari's invention of the crankshaft (and the crank mechanism) is considered the most important single mechanical invention after the wheel, as it transforms continuous rotary motion into a linear reciprocating motion, and is central to modern machinery such as the steam engine, internal combustion engine (where it converts in the other direction) and automatic control.

The connecting rod was also invented by al-Jazari, and was used in a crank and connecting rod system in a rotating machine he developed in 1206, in two of his water-raising machines: the crank-driven saqiya chain pump and the valve-operated double-action reciprocating piston suction pump.

Design and construction methods

The following important design and construction methods were introduced in al-Jazari's work for the first time:

• Lamination of timber to reduce warping
• Static balancing of wheels
• Use of wooden templates
• Use of paper models to establish a design
• Calibration of orifices
• Grinding of the seats and plugs of valves together with emery powder to obtain a watertight fit
• Casting of metals (such as brass and copper) in closed mould boxes with green sand
• Use of tipping buckets that discharge their contents automatically
• Use of rolling balls to sound the hours on cymbals and operate automata (currently used in toys)

Escapement mechanism in a rotating wheel

Al-Jazari invented a method for controlling the speed of rotation of a wheel using an escapement mechanism.

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." This was first invented by al-Jazari. Professor Lynn Townsend White, Jr. wrote:

"Segmental gears first clearly appear in Al-Jazari, in the West they emerge in Giovanni de Dondi‘s astronomical clock finished in 1364, and only with the great Sienese engineer Francesco di Giorgio (1501) did they enter the general vocabulary of European machine design."

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.

Crank-driven saqiya chain pump

The first known use of a crankshaft in a chain pump was in one of al-Jazari's saqiya machines.

Geared and hydropowered 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.

Saqiya chain pump with minimal intermittency

The concept of minimizing intermittent working is first implied in one of al-Jazari's saqiya chain pumps.This was for the purpose of maximising the efficiency of the saqiya chain pump.

Double-action suction pump with valves and reciprocating piston engine

In 1206, Al-Jazari described the first suction pipes, suction pump, double-action pump, reciprocating piston engine, and valve, when he invented a twin-cylinder reciprocating piston pump, which seems to have had a direct significance in the development of modern engineering. 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 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 earliest conversion of rotary to reciprocating motion, via the crank-connecting rod mechanism.

This water-raising machine was also driven by hydropower rather than manual labour, and incorporated the use of an axle with a paddle wheel and vertical gear-wheel, a horizontal gear-wheel with a peg and slot-rod, connecting rods with staple-and-ring fittings, and copper discs.

For these reasons, this invention is considered important to the development of modern machinery, including the steam engine, modern reciprocating pumps, internal combustion engine, artificial heart, bicycle, bicycle pump, etc.

Water-powered saqiya chain pump

Al-Jazari invented a water-raising saqiya chain pump which was run by water power rather than manual labour. This is the first known description of a water-raising machine being operated by water power. Machines like this have been supplying water in Damascus since the 13th century up until modern times. They were in everyday use throughout the medieval Islamic world.

Clocks

Astronomical clocks

Al-Jazari invented monumental water-powered astronomical clocks which displayed moving models of the Sun, Moon, and stars. His largest astronomical clock, which was about 11 feet high, displayed the zodiac and the solar and lunar orbits. Another innovative feature of the clock was a pointer which travelled across the top of a gateway and caused automatic doors to open every hour.

Candle clocks

Al-Jazari described the most sophisticated candle clocks known to date. These clocks were designed using a large candle of uniform weight and cross section, whose rate of burning was known, which was placed in a metal sheath with a fitted cap. The bottom of the candle rested on a shallow dish that had a ring on its side connected through pulleys to a counterweight. As the candle burned away, the weight pushed it upward at a constant speed, while an automaton was operated from the dish at the bottom of the candle.

Elephant clock with automaton, regulator and closed loop system

Main article: Elephant clock

The elephant clock described by al-Jazari in 1206 is notable for several innovations. It was the first clock in which an automaton reacted after certain intervals of time (in this case, a humanoid robot striking the cymbal and a mechanical robotic bird chirping), the first mechanism to employ a flow regulator, the earliest example of a closed-loop system in a mechanism, and the first water clock to accurately record the passage of the temporal hours to match the uneven length of days throughout the year.

The float regulator employed in the clock later had an important influence during the Industrial Revolution of the 18th century, when it was employed in the boiler of a steam engine and in domestic water distribution systems.

Mechanical clocks

Al-Jazari invented the first mechanical clocks driven by water and weights. These included geared clocks and a portable water-powered scribe clock, which was a meter high and half a meter wide. The scribe with his pen was synonymous to the hour hand of a modern clock. This is an example of an ingenious water system by al-Jazari. Al-Jazari's famous water-powered scribe clock was reconstructed successfully at the Science Museum (London) in 1976.

Water clocks

Al-Jazari invented water clocks which employed automata to mark the passage of time, including mechanical birds which discharge pellets from their beaks onto cymbals, doors which opened to reveal humanoid robots, rotating Zodiac circles, humanoid robot musicians who strike drums or play trumpets, etc. He introduced pulley systems and tripping mechanisms as means of transmitting power from the prime movers to the automata.

The largest of his water clocks had a working clock face that was 11 feet high and 4.5 feet wide, and a drive which came from the steady descent of a heavy float in a circular reservoir. He introduced the use of a float chamber and the method of Feedback control in order to maintain a constant outflow from the reservoir. Another innovative feature of the clock was how it recorded the passage of temporal hours, which meant that the rate of flow had to be changed daily to match the uneven length of days throughout the year. This was achieved with the use of a pipe leading from the float chamber into a flow regulator which was accurately calibrated using trial and error methods.

Al-Jazari invented another type of clock which incorporated a closed-loop system, where the clock worked as long as it was loaded with metal balls with which to strike a gong. Al-Jazari also invented water clocks with oil lamps and automatic clocks.

Automata

Automated humanoid waitress

Al-Jazari invented an automated humanoid waitress who served drinks at parties. Like most other automata by al-Jazari, it was driven by hydropower.

Automated moving peacock

Al-Jazari invented the earliest automated moving peacocks, which were also driven by hydro-power.

Fountains and musical automata with hydraulic switching

Al-Jazari's work described fountains and musical automata, in which the flow of water alternated from one large tank to another at hourly or half-hourly intervals. This operation was achieved through his innovative use of hydraulic switching.

Programmable humanoid robot

Al-Jazari is credited with creating the earliest forms of a programmable humanoid robot in 1206. Al-Jazari's automaton was originally a boat with four automatic musicians that floated on a lake to entertain guests at royal drinking parties. His mechanism had a programmable drum machine with pegs (cams) that bump into little levers that operated the percussion. The drummer could be made to play different rhythms and different drum patterns if the pegs were moved around.

Other automata

Al-Jazari also designed and constructed a number of other automata, including automatic machines, home appliances, and musical automata powered by water. Al-Jazari also invented water wheels with cams on their axle used to operate automata.

Other inventions

Automatic gate

Al-Jazari invented the earliest known automatic gates, which were driven by hydropower. He also created automatic doors as part of one of his elaborate water clocks.

Mechanical controls

Al-Jazari first described the use of mechanical controls in a variety of devices he invented, including:

• Metal door
• Combination lock
• Lock with bolts

Other mechanical devices

Some of al-Jazari's other mechanical devices include:

• Valve
• Hand washing devices (including Wudu machines)
• Trick drinking vessels
• Phlebotomy measures
• Linkage
• Hydraulic devices
• Water wheels with cams on their axle used to operate automata
• Water pumps
• Water level
• Construction of pots and pans for wine making
• Construction of ewers and bowls for use as cups
• Pools and fountains
• Devices able to elevate water from shallow wells or flowing rivers
• Several musical instruments
• Other machines working by water
• Other sundry mechanisms

See also

• Inventions in the Muslim world
• Muslim Agricultural Revolution
• Islamic Golden Age
• Islamic science
• List of Arab scientists and scholars

References

• Al-Jazarí, The Book of Knowledge of Ingenious Mechanical Devices: Kitáb fí ma'rifat al-hiyal al-handasiyya, Springer, 1973 edition.[1]
• Hill, Donald Routledge, A History of Engineering in Classical and Medieval Times, 1996.[2]

External links

• The Automata of Al-Jazari
• "Al-Jazari, the Mechanical Genius" at MuslimHeritage.com
• "The Machines of Al-Jazari and Taqi Al-Din" at MuslimHeritage.com
• "How Islamic inventors changed the world" article in The Independent
• ADVANCES IN COMPUTER AND INFORMATION SCIENCES: FROM ABACUS TO HOLONIC AGENTS From:Tuncer Ören, Professor Emeritus School of Information Technologies