The historical setting
Badī az-Zaman Abu l-Izz ibn Ismāīl ibn ar-Razāz al-Jazarī was a polymath, scholar, inventor, mechanical engineer, artisan and artist from the Jazira in Mesopotamia of the Artuqid period. 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. 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.
Pumps and mechanical design
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. Al-Jazari's suction piston pump could lift 13.6 metres of water, with the help of delivery pipes. It was not, however, any more efficient than the noria commonly used by the Muslim world at the time. Al-Jazari cited the Byzantine siphon used for discharging Greek fire as an inspiration for his pump.
Automata for washing and entertainment
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.
Water, candles, and clocks
Al-Jazari's candle clock also included a dial to display the time and, for the first time, employed a bayonet fitting, a fastening mechanism still used in modern times. 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) and the first water clock to accurately record the passage of the temporal hours to match the uneven length of days throughout the year. Al-Jazari's largest astronomical clock was the "castle clock", which was a complex device that was about 11 feet (3.4 m) high, and had multiple functions besides timekeeping.
It included a display of the zodiac and the solar and lunar orbits, and an innovative feature of the device was a pointer in the shape of the crescent moon which travelled across the top of a gateway, moved by a hidden cart, and caused automatic doors to open, each revealing a mannequin, every hour. Another feature of the device was five automata musicians who automatically play music when moved by levers operated by a hidden camshaft attached to a water wheel.