Short answer
Al-Jazari was a 12th-century engineer who served the Artuqid rulers of eastern Anatolia and, in 1206, completed The Book of Knowledge of Ingenious Mechanical Devices. The illustrated book explains how to build water clocks, fountains, pumps and automata, including mechanical musicians and a figure that serves drinks.
Follow-up question How do al-Jazari's machines connect to computers and AI?
Al-Jazari was an engineer who wrote one of the great practical manuals of the Middle Ages. His manual, titled Book of Knowledge of Ingenious Mechanical Devices and finished in 1206, is not a collection of wonders described from a distance. It is a builder's guide, with step-by-step instructions and painted diagrams for clocks, fountains, water-raising machines and automata, which are machines that move by themselves.
His full name is long, Badi' al-Zaman Abu al-'Izz ibn Isma'il ibn al-Razzaz al-Jazari, but he is usually called simply al-Jazari. For anyone curious about the roots of automation and computing, his book is a landmark because it treats self-running machines as things you can design, test and improve.
When and where he worked
Almost everything known about al-Jazari comes from his own book. He served as chief engineer at the palace of the Artuqids, the branch of the dynasty that ruled from Mardin in eastern Anatolia, in what is now southeastern Turkey. His father had held the same post before him. The Metropolitan Museum of Art gives his dates as 1136 to 1206, which means he completed his book at the very end of a long career.
He stood in a rich tradition. He credits earlier engineers, including the Banu Musa brothers, whose own Book of Ingenious Devices dates from the 9th century, and he explains where he improved on his predecessors. He also stresses that he describes only machines he has built himself.
What the book contains
The book became popular and was copied many times by hand. One copy was made in Syria in 1315 by a calligrapher named Farrukh ibn 'Abd al-Latif. A page from it, now in the Metropolitan Museum of Art in New York, shows his most famous design, the elephant clock, painted in ink, watercolor and gold.
Here are some of the machines the book describes:
| Machine | What it does |
|---|---|
| Elephant clock | A water clock housed in a model elephant. Every half hour a bird on top whistles, a figure drops a ball into a dragon's mouth, and the driver strikes the elephant with his goad. |
| Castle clock | A large astronomical clock with doors that open to reveal figures, and automatic musicians. |
| Drink-serving figure | A humanoid figure that appears through a door with a drink once a set amount has flowed into the cup. |
| Peacock fountain | A hand-washing basin where, as water is used, servant figures appear with soap and then a towel. |
| Musical boat | A boat carrying four mechanical musicians, set afloat on a lake as entertainment for the ruler's guests while they drank. |
| Water-raising machines | Pumps and wheels for lifting water, the most practical work in the book. |
Each design comes with miniature paintings, a medieval style of book illustration, that show both the outside of the machine and its hidden workings.
How his automata work
Most of al-Jazari's automata run on water. The basic method uses a few simple parts:
- A steady flow. Water drips from a tank at a controlled rate, so the flow itself measures time.
- A float. As a container fills, a float rises.
- A trigger. When the float reaches a set height, it tips a lever or releases a ball.
- An action. The lever or ball sets off a visible event: a door opens, a bird whistles, a figure moves.
The peacock fountain shows the idea clearly. Water used for washing drains into a hollow base. A float rises with it and, at a first level, pushes a linkage that makes a servant appear with soap. At a higher level, a second float brings out another servant with a towel. The machine "responds" to how much it has been used, with no person working it.
Try it: Fill a glass under a slowly dripping tap and note how long it takes to reach a line you have drawn. You have built the core of a water clock: a steady flow plus a level that marks time.
How do al-Jazari's machines connect to computers and AI?
The most interesting link is the musical boat. According to the robotics researcher Noel Sharkey, the drummer was most likely controlled by a rotating drum fitted with pegs, which bumped small levers that worked the percussion. Move the pegs to new positions and the drummer plays a different rhythm. If that reading is right, the machine stored a pattern of instructions separately from the mechanism that performed them, and the pattern could be changed. That is the core idea of a program.
His float-and-trigger designs carry a second idea: a machine that acts when a condition is met. "When the water reaches this level, open the door" has the same shape as a line of code that says "if this happens, then do that." Modern software, including the AI systems in the news this year, is built from enormous numbers of such conditions, many of them learned from data rather than set by hand.
None of this makes al-Jazari a computer scientist, and his machines did not think. They were built to delight a royal court and to solve practical problems like raising water. But his book shows a mind that treated automatic behavior as an engineering problem, to be broken into parts, tested by building and written down so others could repeat it. In 2019, as engineers design voice assistants and robots that run without supervision, that habit is exactly what the work still demands.
Sources
- "The Elephant Clock", Folio from a Book of the Knowledge of Ingenious Mechanical Devices by al-Jazari — The Metropolitan Museum of Art, Heilbrunn Timeline of Art History, February 1, 2017
- Ismail al-Jazari — Wikipedia (archived March 2019), February 5, 2019