Experimenting is the greatest science.
One of the most important medieval works in the field of automata is al-Jamiʿ bayn al-ʿilm wa ʿamal, al-nafiʿ fi sinaʿat al-hiyal (The book of knowledge of ingenious mechanical devices) of Al-Jazari from 1206. Ismail Al-Jazari (1136-1206) (full name Al-Shaykh Ra’is al-A’mal Badi’ al-Zaman Abu al-‘Izz ibn Isma’il ibn al-Razzaz al-Jazari) was an influential Arabic scholar and engineer, who lived in the second half of 12th and in the beginning of 13th century. He died at the beginning of 1206, just a few months after he had completed his famous book in January 1206. Al-Jazari was in service at the court of three Artuqid rulers from 1174 until his death, and the above-mentioned book was created in the period 1198-1206 in response to the request of Nasir al-Din Mahmud (r. 1200–1222) of the Artuqids of Hisnkeyfa.
According to his name, Al-Jazari was born in Al-Jazira (the traditional Arabic name for what was northern Mesopotamia and what is now northwestern Iraq and northeastern Syria, between the Tigris and the Euphrates). Like his father and his brother 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 Zangid rulers of Mosul. Apart from Archimedes’ work, Al-Jazari also studied Banu Musa brothers’ contribution in making water fountains.
The book of Al-Jazari describes in detail fifty devices, which are grouped into six categories:
1. Ten water and candle clocks
2. Ten vessels and figures suited for drinking sessions
3. Ten pitchers and basins for phlebotomy and washing before prayers
4. Ten fountains that change their shape alternately, and machines for the perpetual flute
5. Five water-raising machines
6. Five miscellaneous devices
The earliest copy of the book, survived until now (from 1206) is a fine manuscript with excellent illustrations. Each device is described in simple and easy-to-understand Arabic, and each is accompanied by a general drawing. For the complicated devices, the author gave detailed drawings for the components of the device or for subassemblies so that the operation can be understood. There are a total of 174 drawings in the book.
The automata in the book of Al-Jazari included:
1. An automated girl serving drinks (see the upper image)
2. An automated moving peacock driven by hydropower
3. Automatic gates, which were driven by hydropower
4. Several other automata, including automatic machines, home appliances (table devices), and musical automata powered by water
Al-Jazari also invented water wheels with cams on their axle used to operate automata.
The humanoid automata of a girl who could serve water, tea, or drinks, shown in the upper image, is very interesting. 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.
Al-Jazari described a hand-washing automaton (see the upper image), incorporating a flush mechanism, now used in modern flush toilets. It features a girl automaton standing by a basin filled with water. When the user pulls the lever, the water drains and the girl refills the basin.
Al-Jazari’s peacock fountain (see the nearby image) was a more sophisticated hand-washing device, featuring humanoid automata as servants who offer soap and towels. Pulling a plug on the peacock’s tail releases water out of the beak, and as the dirty water from the basin fills the hollow base a float rises and actuates a linkage, which makes a servant figure appear from behind a door under the peacock and offer soap. When more water is used, a second float at a higher level trips and causes the appearance of a second servant figure, this time with a towel! The basin of the peacock fountain formed the basin for performing wudu, and it would have been operated by a servant, who would have pulled the plug and positioned the peacock’s beak, thus allowing the mechanism to release the water into the basin in front of the user.
Al-Jazari described also a musical automaton (see the lower image), which was a boat with four automatic musicians (a harpist, a flutist, and two drummers), that floated on a lake to entertain guests at royal drinking parties. The mechanism featured a programmable drum machine with pegs (cams), that bump into little levers that operate the percussion. The drummer could be made to play different rhythms and different drum patterns if the pegs were moved around. The automata were a robot band, which performed more than fifty facial and body actions during each musical selection.
Unlike other practical inventors of the period, who left little record of their work, al-Jazari had a passion for documenting his work and explaining how he built his incredible machines. Several incomplete copies of his Book of Knowledge of Ingenious Mechanical Devices have survived, including one held by the Topkapi Sarayi Museum in Istanbul, Turkey, prized for its artistic detail and beauty. The text exalts Al-Jazari as Badi al-Zaman (unique and unrivaled) and al-Shaykh (learned and worthy), but it also acknowledges the debt he owed to “ancient scholars and wise men.”