I will open a new category in the blog to address these OOPArts, which will certainly be very interesting. The first of these devices to treat here is the stack of Baghdad.
Baghdad Battery
In 1936, during excavations on a hill Kujut Rabua, a village southeast of Baghdad (Iraq), workers in the Iraqi State Railway Department discovered an old tomb covered with a stone slab. For two months, the Iraqi Department of Antiquities extracted there a total of 613 beads, clay figurines, chiselled bricks and other parts. They were dated to the period of deliveries (years between 248 BC. and 226 AD.). They also found some very unique clay vessels. It is a terracotta cups 15 centimeters high and about 7.5 centimeters in diameter. Emerging from a bituminous plug, an iron rod would be inserted inside a copper cylinder and isolated from it by a plug at its base asphalt; He is welded copper cylinder with its hood a lead / tin alloy.
In 1939 the German archaeologist Wilhelm König, then in charge of the Laboratory of the State Museum of Baghdad, identified it as a probable electric battery. He described his findings at 9 Jahre Iraq, published in Austria in 1940. The first analysis of this object was to introduce within an electrolyte, and connect a lamp which lit very weakly. The official report was drawn up after saying that this object is behaving exactly like a modern electric battery. Copper bears a characteristic blue patina with silver plating.
After the Second World War, Willard Gray, an electronics engineer at the Laboratory of High Voltage, General Electric Company, Pittsfield (Massachusetts, EE. UU.), He built a duplicate of these batteries and filled with copper sulfate ( but he said that it could have used another liquid electrolyte available to the people of Iraq at the time: current grape juice). The battery operated and generated between one and two volts.
Gray said he also introduced a silver statuette, in two hours turned golden. According to him, it had shown that the battery work, and that their use was likely to restore silver objects.
In contrast, the archaeologist König showed what material could have joined the "battery" because among the thousands of archaeological objects found in Mesopotamia was not any metal objects transmitter power (like an iron wire) length enough to join several of these "batteries". König said the goal of these batteries was to provide the electricity needed for electroplating gold and silver (although so far has not found any old object galvanized).
For König and Gray there was nothing easier than to assert that these containers were batteries. However, the hypothesis untenable batteries: no residues were found, not even traces of any electrolyte within the copper cylinder. If these containers had been used as voltage generators should have contained an electrolyte, which, although it would have been a long time, could have been detected at present.
The fact that adding copper sulfate electrolyte is generated a potential difference of 1.5 V, does not mean that actually had been used as batteries, and any other container two metals may generate a low voltage if It is added an electrolytic element.
The experiment Engineer Willard Gray (two hours galvanizing silver statuette electrolyte grape juice) proved to be false. The battery of Baghdad could have generated up to 10 mA. Then to deposit 10 g of gold theoretically be needed almost six days of continuous work (and 10 days to deposit 10 g of silver). In practice this time can double or triple.
If wine, vinegar or other acid is added, the iron rod would disintegrate in just over 1 year. Despite these rods have survived until today, clearly it shows that galvanic coupling was used.
After seeing all this evidence, it seems that perhaps these vessels had been merely receptacles for storing scrolls.
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