1 The batteries of Babylon
A restored Partian jar,
claimed to be
an electric cell
In 1930, the Austrian archaeologist Wilhelm König took part in a German expedition to Warka, which he later directed. In 1931, he was appointed Assistant Director of the Baghdader Antikenverwaltung (the Baghdad Antiquities' Administration), becoming its Director in 1934. In 1938, working for the Iraq Museum in Baghdad, he carried out an excavation on a Parthian site at Khujut Rubu'a, where he found a 15 cm high ceramic vessel. It contained a cylinder of sheet copper soldered with a 60:40 lead/tin alloy, capped with a crimped-in copper disk and sealed with bitumen or asphalt, with a further insulating layer of asphalt on top. This held in place an iron rod suspended in the centre of the cylinder, which showed signs of acid corrosion. He recognised this as an ancient electric battery and experimental copies showed that it was capable of providing a charge of about one volt. Other examples were soon identified, all belonging to the Parthian period (from the mid third century BCE to the early third century CE). König suffered a heart attack in February 1939, as a result of which, he had to return to Germany.
Some writers have seen in this electric cells evidence for a technologically advanced civilisation in remote antiquity. However, it should be remembered that these artefacts are contemporary with the growth and height of the Roman Empire, hardly a period in which such a civilisation would have gone unrecorded, particularly when the Parthian Empire was Rome's principal enemy in the east. Furthermore, although König believed that there is evidence for Mesopotamian electroplating of silvered copper vessels, this is no longer thought to be the case, as the items in question are beieved to have been fire-gilded, using mercury. There are certainly no remains of electric motors, electronic circuitry or even of batteries capable of generating the greater power needed to drive such devices.
There are alternative explanations that derive from the obvious inefficiencies of the pots to act as galvanic cells. The asphalt seal is a complete seal, so there would be no way of obtaining any electricity generated within the pot; this suggests that containment was an important consideration in their design. There are similar objects from Seleucia, which were used for storing sacred papyri and this is at least as likely an interpretation as the battery hypothesis.
2 The Antikythera ‘computer’
The Antikythera mechanism
Shortly before Easter 1900, a Greek sponge diver off the small Aegean island of Antikythera discovered the wreck of an ancient ship filled with artefacts, including bronze and marble statues, dating from 85 to 50 BCE. Among the numerous finds, a small formless lump of corroded bronze and rotted wood lay unregarded at the National Museum in Athens for years. As the wood fragments dried and shrank, the lump split open to reveal the outlines of a series of gear wheels resembling clockwork. Gamma-ray photography allowed the historian of science Derek de Solla Price (1922-1983) to reconstruct the machine’s original appearance.
A reconstruction
of the mechanism
The gear wheels were proportioned to show the movements of the sun, moon and planets. The gears could be moved backwards and forwards, making the device a calculator that could show the positions of planets in the sky at any required date. It is nothing less than an astrolabe, a device well known in the Middle Ages.
Although the device is a remarkable achievement, its status should not be exaggerated. We know that the principles of gearing were understood in the Classical world and what is surprising about the Antikythera object is its uniqueness: no similar gearing mechanisms have survived from antiquity. Furthermore, the mechanism is unlikely to have been built for purely scientific purposes, but is more likely to have been part of an astrologer’s toolkit. It does not show a Copernican solar system, with the planets revolving around sun, but a Ptolemaic system, with the sun and planets revolving around the earth in complex motions. Calling it a ‘computer’ rather than an ‘astrolabe’ only serves to make it sound mysterious and out-of-place!