The Baghdad Battery

History may be rewritten after the discovery of a group of artifacts dating back almost 2,200 years were found surrounding the village of Khuyut Rabbou'a near Baghdad. The artifacts are commonly known by the name 'Baghdad Battery' that was assigned to the ancient relics due to the apparent features seen within the artifact.

The Baghdad Batteries remained hidden from public knowledge until 1938, when Wilhelm Konig an archaeologist who was also the German Director of the National Museum of Iraq, came across the artifacts within the museums collection. Wilhelm Konig later returned to Germany, Berlin due to illness where he published a paper outlining the functions that these objects may have been used for.

According to Wilhelm Konig, the 'Baghdad Battery' was used for electroplating Gold onto Silver objects. Although this can not be entirely proven archaeologists from around the world who have since studied the relics come to relativly the same conclusion, being the relic is a primative battery that resembles a galvanic cell possibly capable of generating between 4 and 5 volts of power.

Design

The relics resemble a Jar made of Terracotta standing 5.5 inches high and 3 incress wide. The top of the jar consisted of a 1.5 inch opening sealed with a plug made of asphalt. Beneath the plug is a verticle curled sheet of copper housing an iron rod. This iron rod pierces the plug poking out the top of the jar. Within the jar the iron rod is surrounded by the curved copper sheet which is not entirly closed over.

Pouring an acidic substance such as Vinegar, Fermented Grape Juice or Lemon juice into the Jar will cause a chemical reaction between the cooper sheet and the iron rod when they are connected producing small amounts of power.

Further experimentations have found that when connecting several replica Jar's together the power generated was sufficent to use in electroplating Gold onto Silver. However this energy would still only last for a short period of time.

Since the discovery the offical dating period of the 'Baghdad Batteries' was set within the Parthian time frame of 250BC to 224AD, as the village of Khuyut Rabbou was Pathian. However the artifacts themselves resemble Terracotta Jars styled between 224AD to 640AD otherwsie known as Sassanid Style.

Non-Electrical Theory

Skeptical archaeologists see the electrical experiments as embodying a key problem with experimental archaeology; such experiments can only show that something was physically possible, they say nothing about whether it actually occurred. Further, there are many difficulties with the interpretation of these artifacts as galvanic cells:

• The asphalt completely covers the copper cylinder, electrically insulating it, so no current can be drawn without modifying the design;
• There are not any wires or conductors with them;
• No widely accepted electrical equipment is associated with them (though controversial stone reliefs depicting arc lights have been suggested);
• An asphalt seal, being thermoplastic, is excellent for forming a hermetic seal for long term storage. It would be extremely inconvenient however for a galvanic cell, which would require frequent topping up of the electrolyte (if they were intended for extended use).

Some observe that the artifacts strongly resemble another type of object with a known purpose - namely, storage vessels for sacred scrolls from nearby Seleucia on the Tigris. Those vessels do not have the outermost clay jar, but are otherwise almost identical. Since it is claimed these vessels were exposed to the elements, it would not be at all surprising if any papyrus or parchment inside had completely rotted away, perhaps leaving a trace of slightly acidic organic residue.

Some have claimed that these artifacts provide evidence of ancient knowledge of electricity, millennia before the conventional dates given for its discovery. However 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. Any basic understanding of electrical theory of these cultures did not allow them to render more robust designs. The facts that using the electrodes in the electrolyte to produce the voltage, and using larger vessels gives a larger current is obvious to us today; but it is unclear if the ancient civilizations realised this.

Whoever made the Baghdad batteries, assuming they were in fact galvanic cells, may not have fully understood the principles. For example, it is well known that the Ancient Greeks were aware of electrostatic electrical phenomena produced by amber, but they regarded it as a mere curiosity or toy and developed no electrical theory or functional devices. For evidence of ancient Parthian knowledge of the ideas of electricity, records of its use await discovery in more concrete terms, such as seeing it discussed in their writings (though they may not have stated it as 'electricity', relating instead a mystical connotation) or gaining a better perception that their "batteries" were designed with a knowledge of electrical theory. A controversy also exists as to whether the Ancient Egyptians could have used such devices.

As electrical generators, the "Baghdad batteries" would be inefficient when compared to modern devices.

Related Resource: Wikipedia.com