"Thetis of the silver feet came to the house of Hephaistos,
imperishable, starry, and shining among the immortals,
built in bronze for himself by the god of the dragging footsteps.
She found him sweating as he turned here and there to his billows
busily, since he was working on twenty tripods
which were to stand against the wall of his strong-founded dwelling.
And he had set golden wheels underneath the base of each one
so that of their own motion they could wheel into the immortal
gathering, and return to his house: a wonder to look at."
-- Homeros, poet, Iliad, XVIII:369-377, 8th century B.C.
"The movements of animals may be compared with those of automatic puppets, which are set going on the occasion of a tiny movement; the levers are released, and strike the twisted strings against one another; or with the toy wagon. For the child mounts on it and moves it straight forward, and then again it is moved in a circle owing to its wheels being of unequal diameter (the smaller acts like a centre on the same principle as the cylinders). Animals have parts of a similar kind...." -- Aristotle, philosopher, On the Motion of Animals, 350 B.C.
"For if every instrument could accomplish its own work, obeying or anticipating the will of others, like the statues of Daedalus, or the tripods of Hephaestus, which, says the poet, 'of their own accord entered the assembly of the Gods;' if, in like manner, the shuttle would weave and the plectrum touch the lyre without a hand to guide them, chief workmen would not want servants, nor masters slaves." -- Aristotle, philosopher, Politics, Book I, 350 B.C.
Sharkey, N., The Programmable Robot of Ancient Greece, New Scientist, Issue 2611, Jul 2007
"When Lionardo was at Milan the King of France came there and desired him to do something curious; accordingly he made a lion whose chest opened after he had walked a few steps, discovering himself to be full of lilies." -- Giorgio Vasari, The Lives of the Most Excellent Painters, Sculptors and Architects (Florence 1550).
Constructing a mechanical lion that could walk, let alone present flowers to the king, can't have been a simple task back in 1515 - even for a genius like Leonardo da Vinci. How he managed this feat remained a mystery until 2000, when US robotics expert Mark Rosheim came to a surprising conclusion.
Pulling together fragments of notes and drawings, Rosheim worked out that the lion was almost certainly powered by a clockwork cart illustrated in da Vinci's Codex Atlanticus (see Illustration) Intriguingly, Rosheim suggested that the cart's steering mechanism was controlled by arms attached to rotating gears. With this design it would have been possible to control the automaton's movements simply by changing the position of these arms - in other words, Rosheim argues, da Vinci's lion was not only clockwork, it was also programmable.
This astonishing idea raised some intriguing questions: was da Vinci influenced by an earlier design? And if so, how far back in history can we trace programmable robots?
In search of answers I followed the technology back through medieval Europe to the Islamic world, where I have found evidence of an even earlier programmable automaton, made in Baghdad by the brilliant 13th-century engineer Ibn Ismail Ibn al-Razzaz Al-Jazari. He created a veritable boatload of programmable robot musicians - effectively a floating jukebox - designed to entertain nobles as they drank and lounged at royal pool parties.
Yet the trail doesn't stop there. It led me even further back past the automata of the Byzantine court and ancient Rome to ancient Alexandria. It was here that Hero, one of the greatest Greek engineers, constructed a programmable robot that pre-dates da Vinci's by 1500 years. ...
This certainly seems like a candidate for a programmable machine, and a translation of Book I of Hero's Peri automatopoietikes (on automata-making) supplied the answer. This theatre was indeed a programmable machine, but not in quite the way I had imagined; there are no cams involved. Surprisingly, Hero used a much more explicit programming strategy than either da Vinci or Al-Jazari. His method of programming is unique in the history of robots. It relied on string. ...
There is also the vexatious question of whether Hero's machine was the first. It is hard to believe that there were no earlier designs. In his book Hero hinted that he was giving us something new in an already established theatrical tradition, but he complained that earlier writers were not clear enough to enable others to copy their robots. He made explicit references to Philo of Byzantium's lost book on automatic theatres from 200 BC, for example. Elsewhere there are references to even earlier automata - for instance, in the 4th century BC Aristotle wrote about automatic puppets and a child's wagon that could move in a circle, describing them as if they were commonplace.
The programmable self-propelled machine might even go back as far as the 8th century BC, according to Homer's Iliad: "[Hephaestus] was making twenty tripods that were to stand by the wall of his house, and he set wheels of gold under them all that they might go of their own selves to the assemblies of the gods, and come back again - marvels indeed to see." It looks like the search for the earliest programmable robot is far from over.