Baghdad Battery : The Missing Artifact

The Baghdad Battery, sometimes referred to as the Parthian Battery, is the common name for a number of artifacts created in Mesopotamia, possibly during the Parthian or Sassanid period (the early centuries AD). Some researchers have seen it in ancient Egyptian wall carvings or in ancient texts evidence for ancient electricity. Though these claims generally lack physical proof, there is one particular ancient artifact that is believed by some scientists to be an example of an electrical power source. Despite its plain appearance, this small, undecorated jar may change the accepted view of the history of scientific discovery. The object, thought to be a 2,000 year-old electric battery, was found in 1936 by workers moving earth for a new railway in the area of Khujut Rabu, southeast of Baghdad. The battery appears to have been unearthed in a tomb of the Parthian Period (247 B.C – A.D.228).

The artifacts consist of ~130 mm (~5 inch) tall terracotta jars (with a one and a half inch mouth) containing a copper cylinder made of a rolled-up copper sheet, which houses a single iron rod and some fragment of asphalt. The asphalt had been used to seal the top and bottom of the copper cylinder, as well as to hold the iron rod in place in the center of the cylinder. The use of an asphalt sealing indicated that the object had once contained liquid of some sort, as is also suggested by traces of corrosion on the copper tube, which was probably caused by an acidic agent, perhaps vinegar or wine. This has led some scholars to believe lemon juice, grape juice, or vinegar was used as an acidic agent to jump-start the electrochemical reaction with the two metals.

Components Inside the Battery

At the top, the iron rod is isolated from the copper by bitumen plugs or stoppers, and both rod and cylinder fit snugly inside the opening of the jar which bulges outward towards the middle. The copper cylinder is not watertight, so when the jar was filled with a liquid containg the type of acid found in orange juice, this would surround the iron rod as well. The artifact had been exposed to the weather and had suffered corrosion, although mild given the presence of an electrochemical couple. Similar artifacts were found in the nearby cities of Seleucia (where the jar contained papyrus rolls) and Ctesiphon (Where it contained rolled bronze sheets).

In 1938, German archaeologist Wilhelm Konig, then director of the Baghdad Museum Laboratory, came upon the strange object, or a series of objects (accounts differ) in a box in the museum basement. After a close examination, he realized that the artefact closely resembles a galvanic cell, or a modern electrical battery. Konig subsequently published a paper suggesting that the object was an ancient battery, possibly used for electroplating (transferring a thin film of gold or silver from one surface to another) gold onto silver objects. He also theorized that several batteries could have been attached to each other to increase their output. The most conservative date for the battery is now thought to be somewhere between 250 B.C. and A.D. 640, but the first known electric battery, the Voltaic pile, was not invented by Italian physicist Alessandro Volta until 1800. K├Ânig thought the objects might date to the Parthian period (between 250 BC and AD 224).

Baghdad Battery

However according to Dr. St. John Simpson of the Near Eastern department of the British Museum, their original excavation and context were not well recorded (see stratigraphy), so evidence for this date range is very weak. Most of the components of the objects are not particularly amenable to advanced dating methods. The ceramic pots could be analysed by thermoluminescence dating, but this has apparently not yet been done; in any case, it would only date the firing of the pots, which is not necessarily the same as when the complete artifact was assembled.

Another possibility would be ion diffusion analysis, which could indicate how long the objects were buried. So if this was a primitive battery, where did the ancient Parthians acquire the knowledge to assemble it, and how did it work? After reading Konig’s paper, Willard F.M. Gray, an engineer at the General Electric High Voltage Laboratory in Pittsfield, Massachusetts, decided to construct and test a replica of the ancient battery. When he filled the clay jar with grape juice, vinegar, or copper sulphate solution, he found that it generated about one and a half to two volts of electricity.

In 1978, Egyptologist Dr. Arne Eggebrecht, at the time director of the Roemer and Pelizaeus Museum in Hildesheim, Germany, constructed a replica of the Baghdad Battery and filled it with grape juice. This replica generated 0.87 volts, which he used to electroplate a silver statuette with gold; the layer deposited being a mere 1/10,000 of a millimetre thick. As a result of this experiment. Eggebrecht speculated that many ancient items in museums that are presumed to be manufactured from gold may instead be gold-plated silver. More replicas of the Baghdad artefact were made in 1999 by students under the supervision of Dr. Marjorie Senechal, professor of mathemathics and the history of science at Smith College in the Massachusetts. The students filled one replica jar with vinegar, and it produced 1.1 volts.

Judging by these experiments, the Baghdad Battery was obviously able to produce a small current, but what would it have been used for? Even if it is accepted that the "Baghdad batteries" were in fact electrical devices, this provides no evidence of any real knowledge of electrical phenomena. Thales of Miletus was aware of electrostatic phenomena produced by amber, without possessing any theoretical explanation. As electrical power supplies, the "Baghdad batteries" would be inefficient when compared to modern devices. Luigi Galvani formulated a similar electrochemical couple experiment in the 1780s and, 20 years later, Alessandro Volta developed enough theory to convert Galvani's simple experiment into the efficient voltaic pile, producing around 30 volts of continuous current using devices which were much larger than known Baghdad relics. Within two or three more years Sir Humphry Davy was using voltaic piles that produced 1,000 volts and enough current to run an arc lamp.

The most popular theory is the one originated by Konig, that when those cells were connected together in a series, the current generated would have been enough for electroplating metals. Konig found Sumerian copper vases plated with silver, dating back to 2500 B.C., which he speculated could have been electroplated using similar batteries to that discovered in Khujut Rabu, though no evidence of Sumerian batteries has ever been found. Konig pointed out that craftsmen in modern-day Iraq still use a primitive electroplating technique to coat copper jewelry with a fine layer of silver. He thought it possible that the method was in use in the Parthian period and had been passed on down the years.

In a slightly different form, the technique is known today in a process called gilding, where a layer of gold or silver is applied to a piece of jewelry. Another theory regarding the electrical use of the batteries is that they were used medicinally. Ancient Greek and Roman writings indicate that there was a fairly sophisticated knowledge of electricity in the ancient world. The Greeks mention how pain could be treated by applying electric fish to the feet; sufferers would stand on an electric eel until the inflamed foot become numb. Torpedo or electric rays possess two electric organs behind their eye, and discharge 50 to 200 volts at 50 amps, which they use as a weapon to stun small prey that swim above them.

The Roman writer Claudian described how a torpedo was caught on a bronze hook and emitted an effluence which spread through the water and up the line to give the fisherman a shock. It is recorded that Roman doctors would attach a pair of these electric rays onto patient’s temples in order to treat a range of illnesses, from gout to headaches. Ancient Babylonian doctors are also known to have used electric fish as a local anesthetic.

The ancient Greeks also discovered one of the earliest examples of static electricity; when they rubbed amber (in Greek, electron) against a piece of fur, they found that amber would afterward attract feathers, dust particles, and pieces of straw. However, although the Greeks noticed this strange effect, they had no idea what caused it and probably regarded it as a mere curiosity. But not everyone is convinced of the practicality of the battery for the treatment of pain.

The main problem with the theory of medicinal use is the very low voltage the battery produces, which some doubt would have had any noticeable effect on anything other than very minor pain. Again though, if a series of these batteries were connected together, there could have been enough electricity generated. Staying with an medicinal/electrical explanation for the Baghdad Battery, Paul T. Keyser of the University of Alberts in Canada, has postulated another use for the battery based on finds of bronze and iron needles discovered with other battery-like devices unearthed at Seleucia, not far from Babylon. His suggestion, published in a 1993 paper, is that these needles may have been used for a kind of electro-acupuncture, a treatment already in use in China at the time.

Some researchers favour a ritual use for the Baghdad Battery. Dr. Paul Craddock, an expert in historical metallurgy from the Department of Scientific Research at the British Museum, has proposed that a group of these ancient cells connected together may have been concealed inside a metal staue. Worshippers coming into contact with the idol would get a small electric shock, similar to that of static electricity, possibly when giving the wrong answer to a question posed by the priest.

Perhaps this mysterious tingling effect would have been thought of by the worshippers as evidence of magic, and the power and mystique of the particular priest and temple would thus be greatly enhanced. Unfortunately, unless such statues are actually recovered, a ritual use for the cells remains just another fascinating theory. Despite the repeated tests with replicas of the Baghdad batteries, sceptics argue that there is no proof that they ever functioned as electric batteries. They note that the ancient people supposedly responsible for this technology, the Parthians, were known as great warriors, but not regarded for their scientific achievements.

Skeptics also point to the fact that despite the extensive historical records we have concerning this area and period, there is no mention of anything connected with electricity anywhere. There are also no archaeological finds from the Parthian period that have been proved to be electrogilded, and no evidence of wires, conductors, or more complete examples of ancient batteries. Some researchers have also disputed the results from experiments with replicas of the battery, claiming that they have been unable to duplicate the results themselves.

Dr. Arne Eggebrecht’s experiments in particular, have come under fire. According to Dr. Bettina Schmitz, a researcher at Roemer and Pelizaeus Museum (the same institution where Eggebrecht did his 1978 experiments with reproductions of the battery), there are no photos or written documentation of the experiments which Eggebrecht undertook. A favored alternative explanation of these sceptical of the electrical battery theory is that the jars acted as storage vessels for sacred scrolls, perhaps containing rituals of some sort written on organic material such as parchment or papyrus. If such organic materials had rotten away, the sceptics claim, they would leave a slightly acidic organic residue, which would explain the corrosion on the copper cylinder.

They believe that an asphalt seal such as that on the Baghdad battery, while not particularly practical for a Galvanic cell, would be perfect as a hermetic seal for storage over an extended period. That the Baghdad batteries would be inefficient compared to modern devices, even when several were connected together, is not in doubt. But the fact remains that the device does actually function as an electric cell. What is probable is that, similar to the ancient Greeks with amber, the makers of the object did not properly understand the principle involved. But this is not unusual.

Many innovations, such as gunpowder and herbal medicines, were developed before their fundamentals were soundly grasped. Nevertheless, even if the Baghdad artefact is one day proved to be an ancient electric battery, it would not be evidence of any genuine comprehension of electrical phenomena 2,000 years ago. The question now remains whether the Baghdad Battery was an isolated find. Can its manufacturers have been the only people in antiquity to discover – probably by accident – electricity?

Obviously there is a need for further evidence, whether literary or archaeological, because based on current knowledge, it is likely that the battery is indeed a unique find. Tragically, in 2003, during the war in Iraq, the Baghdad Battery was looted from the National Museum, along with thousand of other priceless ancient artifacts. Its current whereabouts are unknown.

(Sources : Hidden History by Brian Haughton; and Wikipedia)
(Pic sources : pic 1 taken from Hidden history by Brian Haughton page 129;pic2;pic3

Written By Tripzibit on Apr 13, 2009 | 05:01

Related Posts with Thumbnails

3 komentar:

ikogsakanding said...

great blog... thanks for sharing....


tripzibit said...

(ikogsakanding) You're welcome :)

Toshiba Laptop Battery said...

The baghdad battery is immensely controversial in all ways, and will continue to be so until some finds docuented proof. It is too bad that so many important historical documents have been lost, and I think we could have had such a technology back then, and the knowledge of how to use it.