Baghdad Battery

First described by Wilhelm König in 1938. Whether the assembly was an electrical cell, a scroll storage container, or another artefact is unresolved.

The artefacts at issue — clay jars from Khujut Rabu, each holding a copper cylinder around an iron rod — are real and well documented; it is their purpose that remains contested. König, then directing the Baghdad museum, proposed that the assembly was a galvanic cell, and the suggestion has been repeated ever since, sometimes with the embellishment that such cells were used to electroplate gold. We treat that reading with caution. Replica experiments have shown that, filled with an acidic electrolyte such as vinegar or grape juice, the jars can produce a small voltage; but capability is not evidence of intent, and no contemporary text, wiring, conductor, or plated object has ever been found to accompany them.

The mainstream archaeological view, which we record as the better-supported one, is more prosaic: that these were storage vessels, the corroded iron and copper consistent with sacred scrolls or papyri sealed inside and since decayed. The “ancient battery” remains a possibility rather than a finding. We hold the claim against the documentary record, set out both readings, and decline to settle a question the evidence does not yet settle.