Few objects in the record have been asked to do as much work as the small clay pot filed by its own museum as the Baghdad Battery. It stands about fifteen centimetres. Inside it is a copper tube nine centimetres long and twenty-six millimetres across, and down the middle of that tube runs an iron rod, now entirely rust. From those three components have been built a lost science, a visitation, and a durable secondary industry in television. The Bureau has read the file. What follows is every purpose that has been proposed for the jar, set out in descending order of the confidence with which it was proposed.
The Discovery
The jar came up in 1936 at Khujut Rabu, on the edge of Baghdad and within a morning’s ride of Ctesiphon, capital first of the Parthians and afterwards of the Sasanians. Its style is ordinary domestic pottery of the Sasanian period, AD 224 to 640. Babylon is eighty-five kilometres to the south, at Hillah, and Babylon’s empire had been over since Cyrus took the city in 539 BC. The Babylonian Battery is therefore neither Babylonian nor from Babylon, and the third word has been in dispute for the better part of a century.
The man who put it there was Wilhelm König, an Austrian painter by trade who had joined the Baghdad Antiquity Administration in 1931 and whose duties amounted to looking after the objects. He observed that a copper tube standing around an iron rod, the two kept from touching and the whole sealed with asphalt, is the arrangement of a galvanic cell. In 1938 he published the observation in Forschungen und Fortschritte under a title ending in a question mark: Ein galvanisches Element aus der Partherzeit? The question mark did not survive translation into English, and has not been seen since.
Serious Theories
Electroplating
The proposal that has travelled furthest is electroplating: that the jar drove a current through a bath and laid a skin of gold over something cheaper. It is a tidy idea with one hole in it, and the hole is the size of the region. Eighteen centuries of Mesopotamian metalwork have been excavated, catalogued and analysed, and not one electroplated object has come out of the ground. Electrodeposition is otherwise first performed by Luigi Brugnatelli in 1805, on a pile borrowed from Volta, and patented for trade by the Elkingtons in 1840.
Religious or Medicinal Use
A second reading makes the jar temple furniture: a device for delivering a small, startling shock to a supplicant, who would attribute it correctly to a god and incorrectly to that god’s opinion of him. The theory requires no lost science, only a lost priest, which is a considerable saving. Its difficulty is the shock. As sealed, the assembly cannot deliver one — the iron rod projects through the asphalt plug, but the copper tube does not, so there is nothing on the outside of the jar to attach the second wire to.
Medical Therapy
Electrotherapy is the one proposal with a genuine ancient precedent, and the precedent involves no jar whatever. About AD 47 the Roman physician Scribonius Largus set down in the Compositiones that a live torpedo ray, held against the place that hurts, will take away a headache, even a chronic and unbearable one, and will do the same office for gout. It is an early and entirely serious description of peripheral nerve stimulation. The ancients did have a battery. It swam, it was replaced weekly, and nobody ever mistook it for a pot.
Electrostatic Experiments
It has been suggested that the jar is apparatus — that somebody in the Tigris valley was investigating a phenomenon for its own sake, and this is what survives of the bench. Nothing forbids it and nothing whatever supports it. When an ancient culture does build a scientific instrument, the evidence is not shy about it: the Antikythera mechanism came off a wreck in 1901 in eighty-two pieces, holds at least thirty bronze gears, turns on a principal wheel of 223 teeth, and carries inscriptions that X-ray tomography read back out in 2005. That object has never required an advocate. This one has had eighty-six years of them.
Chemical Storage
The dullest theory is the one the field actually holds, and it is dull in the specific way that correct explanations tend to be. Sealed jars of this class turn up across the neighbourhood — at Seleucia over the Tigris, and at Ctesiphon itself — and when they are opened they hold decomposed fibre rolls: papyrus, wound up and put away. In 1932 Ernst Kühnel described the Ctesiphon examples as containers for conjurations and blessings. On that reading the copper tube is the case, the rod holds the roll, and the asphalt keeps out the damp. The Babylonian Battery is a document wallet, which is the most Mesopotamian thing it could possibly turn out to be.
Religious Symbolism
Failing all of the above there is symbolism, the explanation of last resort in this discipline and the only one that cannot be disproved. On this account the jar produced nothing and represented everything: a sealed vessel with a metal heart, standing in a niche, signifying power. The Bureau observes that this is also an exact description of a jar with a document in it, and that the distance between the two theories is made up entirely of what the reader would prefer to have been true.
Not So Serious Theories
Everything above has been argued in print by somebody holding a post. Below this line the standard falls away and the jar passes into the literature of the out-of-place artefact — that class of object whose alleged context, if it held, would rearrange the calendar. The Bureau prints the following without endorsement and in the order received.
Ancient Aliens
The jar was a gift, left by visitors who wished to advance us and elected to do so with a nine-centimetre copper tube rather than, say, writing anything down. The theory is untestable, which is its attraction, and it obliges the visitors to have crossed the interstellar distances and then produced a cell of under half a volt, which is its difficulty. Ten replicas wired in series were made to yield 4.33 volts for a television programme. That is a doorbell.
The World’s Oldest Flashlight
Priests, it is said, carried the jar through the temple at night in order to read by it. This requires a lamp; the lamp requires a filament; the filament requires tungsten; and tungsten requires 1904. It also requires somebody to explain why a civilisation already in possession of oil and a wick would prefer half a volt.
The Babylonian Electric Eel
A related proposal makes the jar a transport flask for the current of a living animal, captured, decanted, and carried to a party. The animal is invariably the electric eel, which reaches 860 volts in the strongest species and lives exclusively in South America — some eleven thousand kilometres from Khujut Rabu, across an ocean that had not yet been crossed, and beyond a continent nobody in the story knew about.
Ancient Babylonian Karaoke Machine
Here the jar powers a microphone and the high priests take turns. The objection is not the electricity, which is merely absent. It is that amplification also wants a diaphragm, a coil, a magnet and a horn, none of which has been dug up, and a repertoire, which in this period would have had to be issued in cuneiform on tablets weighing roughly as much as the audience.
The First Electric Toothbrush
Dental hygiene at court, powered by the jar. Mesopotamian dentistry is in fact documented and it is not encouraging. The standard account of toothache held that a worm had petitioned the gods for somewhere to live and been granted the gums; the prescribed treatment was beer and oil applied to the tooth while the worm’s own words were recited back at it three times. Nobody in that procedure is holding a brush.
Babylonian Bug Zapper
A summer evening on the river, and something to keep the mosquitoes off it. Such a device wants a grid held at some thousands of volts; the jar offers under one. It would further require the insect to complete the circuit of its own free will, which, in fairness to the theory, is precisely what mosquitoes do.
Babylonian Love Detector
The jar as a polygraph of the heart: the sweetheart is wired in, the questions are put, and every false answer earns a jolt. Since the jolt is administered on the operator’s judgement rather than the subject’s physiology, the instrument does not detect a lie; it enforces an agreement. This makes it the most historically plausible device in the entire list.
Babylonian Remote Control
The king at leisure, opening doors from his couch. A remote control wants a transmitter, a receiver and a code, and the palace already held all three in a more reliable arrangement: a servant, a doorway, and the word for open. Antiquity had solved this so completely that the modern version is a regression.
Ancient Babylonian Time Machine
A short excursion forward to see what is coming. Were any Mesopotamian ever to have made the trip, the evidence should be trivial to find, because the one thing that culture never once failed to do was write things down: somewhere between five hundred thousand and two million cuneiform tablets have come out of the ground, and not one of them mentions the telephone.
Babylonian Brainstormer
Inventors seated in a ring and shocked at intervals to loosen the ideas out of them. The wheel is usually offered as the output. The wheel is attested in Mesopotamia from about 3500 BC, some three and a half thousand years before this jar was thrown, which makes the session either very long or very late.
Babylonian Espresso Maker
Coffee for the night shift in the scriptorium. Coffee is Ethiopian, it is not drunk anywhere on the record before roughly the fifteenth century AD, and it reaches Baghdad about a thousand years after this jar was buried. The scribes stayed awake on beer, which they were also paid in, and it is the only detail in this section that comes with a receipt.
Babylonian Disco Light
Flashing colour, dancers, a festival. The jar cannot flash, having no switch; it cannot colour, having no filter; and were it somehow to manage both, it would not be visible from the far side of the room. What it can do is stand in a niche and be dark, which is what it did, for approximately fifteen centuries, without a single reported failure.
Ancient GPS Device
Navigation, last: the jar as a guide through a city without street signs. Mesopotamia did keep maps — the Babylonian Map of the World, BM 92687 in the British Museum, draws the whole earth as a disc with Babylon on it and a bitter river running all the way round the outside — and it kept a working direction system besides, which was the ziggurat. Visible from everywhere, immovable, and requiring no power of any kind.
Wilhelm König: The Archaeologist Behind the Babylonian Battery
König was a painter. He was born in Vienna, he came out to Iraq, and in 1931 he was made assistant to the German head of the Baghdad Antiquity Administration with the title of Direktor, which in that office meant the man responsible for the objects. He was not a physicist and never once said he was. He looked into a storeroom, recognised a shape he knew from a schoolbook, and asked a question in public. Everything that has happened since is what other people did with the question after removing its punctuation.
The rest of his work was the ordinary work of the department, and it has outlasted the battery. The plaster casts of Iraq Museum objects that stand today in the Vorderasiatisches Museum in Berlin were made by him. He wrote his nine years in the country up as Im verlorenen Paradies. Neun Jahre Irak, published at Baden bei Wien in 1940. He went home to Vienna in February 1939 with blood poisoning, having spent most of a decade in the field and eleven months as a sensation.
The field has never agreed with him and, on the whole, has never been unkind about it either. Elizabeth Stone of Stony Brook, who has dug in Iraq for decades, put the consensus about as flatly as it can be put when she said she did not know a single archaeologist who believed these were batteries. The objection is not that the jar cannot make a current — a replica will, feebly, given vinegar and patience — but that a current is not evidence of an intention, and there is nothing in the ground to supply the intention.
The jar itself has not been seen since 2003. It was in the Iraq Museum in Baghdad and its present whereabouts are unknown, so the most photographed object in the argument is now the argument’s only missing exhibit. The case for the Babylonian Battery rests where it has rested since 1938: on a shape, a coincidence, and a question mark that somebody threw away.
