The eccentric engineer

E&T on the multiple inventions of al-Jazari, a remarkable 12th century engineer.

I'm told we're expecting a hot, dry summer in the UK. But then I've been told that before. However, on the off-chance that the skies remain blue and the sun beats down, I have been giving some thought to what to do about my vegetables. Being on a water meter, I'm loathe to spend the summer watering them with a hose, but I couldn't bear to see them shrivel and die. So I got to thinking about a bore hole and mediaeval robot musicians - not something that will come as a surprise, I'm sure.

That I should connect the two is thanks to one remarkable engineer who deserves to be better known. Al-Shaykh Ra'is al-A'mal Badi' al-Zaman Abu al-'Izz ibn Isma'il ibn al-Razzaz al-Jazari (1136-1206), thankfully known as just al-Jazari, is a rather elusive figure. We know that he came from the northern part of Mesopotamia and that he was the senior engineer to Nasir Al-Din, the Artuqid king of Diyar Bakr whose dynasty ruled a large chunk of northern Iraq, Anatolia and northern Syria. But what makes al-Jazari really stand out is that he wrote a book, the intriguing 'Book of Knowledge of Ingenious Mechanical Devices'(1206).

Indeed, "ingenious" would be something of an understatement. Al-Jazari's book, containing a bewildering array of machines to make his masters' lives more convenient and entertaining - 50 devices in all with everything from pumps and fountains to blood-letting tools, puts even the likes of Agostino Ramelli to shame.

A great builder of automata, he was one of the first engineers to turn his mind to what we today would call the 'domestic appliance'. In particular, he was fond of building hand-washing machines, which are, of course, very important in Islam. One, the Peacock Fountain, released water through a model peacock's beak, which then tripped a series of floats, the first of which made one figure appear from behind a door proffering a bar of soap, and another with a towel. They just don't make appliances like that any more - I've checked.

Clocks were also a passion. His most sophisticated timepiece, known as the 'Castle Clock' was 3.5m tall and, as well as telling the time, displayed the movement of the constellations of the Zodiac and the orbits of the Sun and Moon. On each hour a figure, accompanied by a tune from five automaton musicians, making it something akin to the first cuckoo clock, appeared from behind a door. More impressively, it could be altered to track the lengths of days over the year.

Long summer evenings gave al Jazari's masters a chance to enjoy one of his more eccentric inventions - the robotic floating band. This consisted of a boat holding four automata in the shape of musicians, rowed by ranks of mechanical oarsmen. The machine would row around for half-an-hour or so on a large lake and then the band would strike up with flutes and drums and cymbals. After a short number, they'd stop and the oarsmen would get back to work. The whole system was operated by a turning drum beneath the deck into which pegs were placed to control the various movements. As the pegs could be repositioned to play different tunes, this was a very early programmable device.

But what does this have to do with my potatoes? Sadly, I don't own a lake or a boat of automatic musicians, but it is thanks to al-Jazari that I can pump water out of the ground. For all the fiendish complexity of his automata, it is not these that make him great.

Hidden away in his discussions of amazing machines, lie the first written descriptions of a host of mechanisms we couldn't live without today. He provides the first description of casting metal parts in closed sandboxes, a method for making watertight valves, the static balancing of large pulley wheels and the use of segmental gears - even the lamination of wood to prevent warping.

But it is in his water-raising devices that he makes his greatest contribution. His two-cylinder reciprocating piston suction pump was, and frankly remains, one of the most useful machines for anyone who needs to get water anywhere: from a thirsty vegetable patch to a thirsty city. But it is also much more than this. This was not only a very serviceable pump; al-Jazari also provides the first references to some of the most important ideas in all engineering.

In the first place, this pump provides the earliest account of a crankshaft, that most essential of devices for turning rotary motion into reciprocal one (or vice-versa). The modern world just wouldn't have got very far without those. It contains the first connecting-rod mechanism, another rather vital element of many engines. If that seems impressive, let's not forget that it also is the first demonstration of the double-acting principle and the first use of a suction pipe - with atmospheric pressure to force water into a pump by creating a partial vacuum.

In fact, a very large number of modern machines simply wouldn't work without the principles first set out by al-Jazari. Indeed, much of the world we take for granted would grind to a halt. And I don't like to think what might happen to my potatoes.

 

The winner of the last caption competition was Jon Ford with: "Well thanks a lot! I'm fighting for my life to put food on the table and you get a KFC without me..."

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