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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Baghdad Battery | 1/3 | https://en.wikipedia.org/wiki/Baghdad_Battery | reference | science, encyclopedia | 2026-05-05T09:17:17.899908+00:00 | kb-cron |
The Baghdad Battery or Parthian Battery Persian: باتری اشکانی ،is the name given to an artifact consisting of a ceramic pot, a tube of copper, and a rod of iron fixed together with bitumen. It was discovered in present-day Khujut Rabu, Iraq in 1936, close to the ancient city of Ctesiphon, the capital of the Parthian (150 BC – 223 AD) and Sasanian (224–650 AD) empires, and it is believed to date from either of these periods. Its origin and purpose remain unclear. Wilhelm König, at the time director of the laboratory of the National Museum of Iraq, suggested that the object functioned as a galvanic cell, possibly used for electroplating, or some kind of electrotherapy. There is no electroplated object known from this period, and the claims are universally rejected by archaeologists. An alternative explanation is that it functioned as a container for magic spells for protection, defense or curses. Ten similar clay vessels had been found earlier. Four were found in 1930 in Seleucia dating to the Sassanid period. Three were sealed with bitumen and contained a bronze cylinder, again sealed, with a pressed-in papyrus wrapper containing decomposed fiber rolls. They had been held in place with up to four bronze and iron rods sunk into the ground, and their cult meaning and use are inferred. Six other clay vessels were found nearby in Ctesiphon. Some had bronze wrappers with badly decomposed cellulose fibers. Others had iron nails or lead plates. The current whereabouts of the artifact are unknown, since the 2003 US-led invasion of Iraq.
== Physical description and dating == Austrian archaeologist Wilhelm König's description of the find, translated into English, included:
In a vase-like container of bright yellow clay, the neck of which had been removed, a copper cylinder was stuck, held in place by asphalt. The vase was about 15cm high; the cylindrical tube with a closed bottom made from sheet copper had a diameter of 26 mm and a height of 9 cm. In the latter a completely oxidized rod of iron was found, held in place by a sort of stopper of asphalt... König stated that the cylinder was "fairly pure copper with traces of zinc, lead and iron." The copper cylinder is not watertight, so if the jar were filled with a liquid, this would surround the iron rod as well. The artifact had been exposed to the weather and had suffered corrosion. König thought the objects might date to the Parthian period, between 250 BC and AD 224. However, according to St John Simpson of the Near Eastern department of the British Museum, their original excavation and context were not well-recorded, and evidence for this date range is very weak. Furthermore, the style of the pottery is Sasanian (224–640). Albert Al-Haik noted original reports from the 1936 dig led by Sherif Yousif and Jawad al-Saffar at Khuyut Rabbou'a, giving the location as an area northeast of Baghdad, "some two miles off the Baghdad eastern bund." W. B. Hafford gives context to the discovery of the artifacts in his reaction video to Milo Rossi's video on the subject.
== Comparable finds == Similar vessels, which can be distinguished primarily by their contents, had previously been found and examined more closely: Four clay vessels were excavated at Seleucia in 1930 under the archaeological direction of Leroy Waterman, University of Michigan. All four were common unglazed ceramic, sealed with bitumen stoppers and between 6 and 8 inches (15 to 20cm) tall. Three of these finds were lying horizontal, held in place by up to four metal rods at the ends and sides. The rods were six to ten inches (15 to 25cm) long, one iron rod per jar and the rest bronze. Each contained a bronze cylinder, sealed at both ends, all three the same size: 1¼ inches (3cm) in diameter and 3 inches (7½cm) long. All three cylinders contained plant matter, one decomposed to flakes, one just a small closely-wrapped core and the other appearing to be a papyrus roll folded over at the ends. The fourth jar was found upright and contained fragments of a small broken glass bottle. Silver coins found in context imply a Sasanian date. In 1931, a German-American excavation expedition led by Ernst Kühnel found six more clay vessels in the immediately neighboring Ctesiphon, including three sealed find objects, each with one, three and ten wrapped and sealed bronze rolls. Inside these bronze wraps were already badly decomposed cellulose fibers. Another clay vessel contained three sealed bronze cylinders. In the other two vessels, which were also sealed, there were plates of originally pure lead coated with lead carbonate in a find specimen; in the other ten heavily corroded iron nails, on which traces of a wrapped organic fiber material could be detected. These finds were also dated to the late Sasanian period.
== Electric battery theory == Its origin and purpose remain unclear. Wilhelm König was an assistant at the Iraq Museum in the 1930s. He had observed a number of very fine silver objects from ancient Iraq, plated with very thin layers of gold, and speculated that they were electroplated. In 1938 he authored a paper offering the hypothesis that the Khujut Rabu jar may have formed a galvanic cell, perhaps used for electroplating gold onto silver objects. This interpretation is rejected by archaeologists and scientists. Two media reports (in 2003 and 2004) stated that corrosion of the metal and tests both indicated that an acidic agent such as wine or vinegar was present in the jar, without giving sources for that information. In 1993, Paul T. Keyser had speculated that "the asphalt seal indicates the presence of liquid" and that because most liquids known at the time were acidic, except for vegetable and mineral oils, that the hypothetical liquid was used as an acidic electrolyte solution to generate an electric current from the difference between the electrode potentials of the copper and iron electrodes.
== Experiments ==