Al-Jazari's Book of Ingenious Mechanical Devices (1206)

The Book of Knowledge of Ingenious Mechanical Devices is an Arabic engineering treatise completed in 1206 by al-Jazari, an engineer at the court of the Artuqid dynasty in Diyarbakır, in what is now south-eastern Turkey. It describes about 50 machines, from water clocks and automata to pumps for raising water, with clear drawings and instructions for building them. It is the most detailed surviving source for medieval mechanical engineering in the Islamic world and one of the most important technical books of the Middle Ages anywhere.

Background: engineering in the Islamic world

Al-Jazari worked in a long tradition. Greek engineers such as Philo of Byzantium and Hero of Alexandria had written on pneumatics and automata, and their works were translated into Arabic in the ninth and tenth centuries, partly through scholars connected with the House of Wisdom in Baghdad. In the same city the three Banu Musa brothers wrote their own Book of Ingenious Devices, around 850, full of trick vessels and self-regulating mechanisms.

Practical engineering was also well developed: water wheels, irrigation machines, mills and water clocks were part of everyday life in the Middle East. Al-Jazari says in his introduction that he had studied the works of earlier scholars and the practice of craftsmen, and that he set out to describe devices he had built or improved himself.

Al-Jazari and the Artuqid court

Al-Jazari’s full name was Badi al-Zaman Abu al-Izz ibn Ismail ibn al-Razzaz al-Jazari. The name al-Jazari refers to al-Jazira, the region between the upper Tigris and Euphrates. Almost everything known about him comes from his own book. He served three successive rulers of the Artuqid dynasty, a Turkish family that governed Diyarbakır (then called Amid) and neighbouring towns, for about 25 years.

The book was commissioned by the ruler Nasir al-Din Mahmud, who reigned from about 1200 to 1222. Al-Jazari finished it in the Islamic year 602, which corresponds to 1206. He is generally thought to have died around the same time, though the exact date is unknown.

The Artuqids were minor princes compared with the Ayyubids of Saladin’s family or the Seljuks of Anatolia, but their cities on the upper Tigris were wealthy and their courts sponsored building, metalwork and learning. Diyarbakır’s massive basalt walls and the Artuqid bridge at Hasankeyf survive as evidence of the engineering skill available in the region. Al-Jazari’s position at court gave him the resources, the workshops and the time to build and test the machines he described, and his book was partly a record of a career in the ruler’s service.

Contents of the book

The treatise is divided into six categories. The first five each contain ten or five machines, and the sixth gathers miscellaneous devices.

Each chapter explains how to make the device, part by part, with measurements and assembly instructions, and is accompanied by a drawing. This practical focus is what makes the book unusual: it was written so that another skilled craftsman could build the machines, not only to impress a patron.

The elephant clock and other water clocks

The most famous device is the elephant clock. A model elephant carries a canopied tower on its back with a driver, a scribe and other figures. Inside the elephant, a float bowl with a small hole slowly sinks in a tank of water, taking about half an hour to fill. As it sinks it pulls cords that release a ball at the top of the tower. The ball triggers a bird to whistle, falls through the mouth of a serpent, tips the serpent and makes the driver strike his drum or cymbal, before the bowl is reset and the cycle begins again.

Modern commentators often read the design as a blend of cultures: the Indian elephant and driver, Chinese-style dragon-serpents and the phoenix-like bird. The castle clock, another water clock, displayed the hours with doors that opened, figures that played music and a zodiac. These clocks were not more accurate than earlier types but combined timekeeping with elaborate display, in the same spirit as the earlier Chinese astronomical clock tower of Su Song.

Pumps, valves and mechanisms

The water-raising machines are of great interest to historians of technology. One machine, driven by a water wheel, uses a crank-like linkage to convert rotary motion into the back-and-forth motion of pistons in a double-acting pump, which sent water up a pipe from both cylinders in turn. Al-Jazari also used segmental gears, conical valves ground to fit their seats, and devices for feeding water at a steady rate.

His book describes techniques such as casting metal in closed moulds with green sand and calibrating orifices for clocks. It shows engineering knowledge that was common among skilled craftsmen of the time but rarely written down.

Myths and facts

Al-Jazari is sometimes called the inventor of the crankshaft, the camshaft or the robot. These claims simplify a more complex picture. His machines do use cams and crank-like mechanisms, and his drinking-party figures are early programmable-style automata, but similar ideas appear in earlier Greek, Chinese and Islamic sources, and his crank-and-slot linkage is not the same as a later engine crankshaft. His real importance lies in the range, precision and clarity of his descriptions.

Another popular idea is that his machines were purely toys for a ruler. Many were indeed entertainments, but the pumps and water-raising devices addressed real practical needs, and the book recorded methods that a working engineer could use.

Manuscripts and legacy

The treatise was copied many times. Over a dozen manuscripts survive, in collections including the Topkapı Palace Library in Istanbul and the Bodleian Library in Oxford. A celebrated illustrated copy made in 1315, under the Mamluks, was later broken up, and its pages are now held by museums such as the Metropolitan Museum of Art in New York and the Freer Gallery of Art in Washington.

Western scholars became interested in the book in the late nineteenth and twentieth centuries. The engineer and historian Donald R. Hill published a full English translation in 1974, which made al-Jazari widely known and showed how much medieval Islamic engineering had been overlooked. Modern working reconstructions of his clocks and pumps, including the large elephant clock in Dubai’s Ibn Battuta Mall, have shown that his designs function as described.

Mechanical clocks with automata later became popular in Europe, as in the Prague astronomical clock, though a direct line of influence from al-Jazari has not been proven.

Timeline

• c. 850: The Banu Musa brothers write their Book of Ingenious Devices in Baghdad.
• Late 12th century: Al-Jazari begins about 25 years of service with the Artuqid rulers of Diyarbakır.
• c. 1200: Nasir al-Din Mahmud becomes Artuqid ruler and later commissions the book.
• 1206 (AH 602): Al-Jazari completes the treatise.
• 1315: A lavishly illustrated copy is made in the Mamluk lands.
• 1974: Donald R. Hill publishes the first complete English translation.

Why it matters

Al-Jazari’s book is a rare written record of how medieval engineers actually designed and built machines. It shows the Islamic world as a centre of practical technology in the thirteenth century and remains a key source for the history of clocks, pumps and automata.