Battery, Baghdad, 250 BCE

The Baghdad Battery is believed to be about 2000 years old (from the Parthian period, roughly 250 BCE to CE 250). The jar was found in Khujut Rabu just outside Baghdad and is composed of a clay jar with a stopper made of asphalt. Sticking through the asphalt is an iron rod surrounded by a copper cylinder. When filled with vinegar – orany other electrolytic solution – the jar produces about 1.1 volts.

There is no written record as to the exact function of the jar, but the best guess is that it was a type of battery. Scientists believe the batteries (if that is their correct function) were used to electroplate items such as putting a layer of one metal (gold) onto the surface of another (silver), a method still practiced in Iraq today.

Method of Construction

Constructed by: Denielle Downes ’00 and Ava Meyerhoff ”99

To recreate this “battery” we shaped clay into the form of a jar. In order to cut the jar in half, we omitted the firing process and instead shellacked the inside surface to make it non-porous to liquid. Using a band saw, we cut the jar in half to show the inner workings. We then proceeded to use the band saw to cut the copper cylinder, the steel rod (no iron available), and the rubber stopper (no asphalt available!). We also cut a piece of glass with a glasscutter to place over one half of the jar. We epoxied the necessary pieces together. We then filled the jar with vinegar and lo and behold the jar produced 1.1 volts.

Resources

James, P. and Thorpe, N. Ancient Inventions. New York: Ballantine Books, 1994

World Wide Web URL: https://unmuseum.mus.pa.us/bbattery.htm