Accession No

1142

Brief Description

Voltaic dry Pile; 1st half of 19th c.

Origin

Maker

Class

electrical

Earliest Date

1800

Latest Date

1850

Inscription Date

Material

metal (copper, zinc, brass); wood; plastic (ebonite); cloth

Dimensions

height 192mm; base diameter 79mm

Special Collection

Provenance

Transfer from the Cavendish Laboratory, University of Cambridge. Listed in the Cavendish Alphabetical and Numerical Catalogues: ‘Volta dry pile’; Cavendish Laboratory, number: E 204.

Inscription

“E 204” (on brass plate on top, added)

Description Notes

Voltaic dry Pile; 1st half of 19th c.;
Vertical pile of 85 cells, each cell consisting of 3 discs: copper, fabric, zinc; copper wires attached to top copper and bottom zinc discs; pile supported between top and bottom circular wooden plates, held in place by three ebonite columns with spherical threaded ebonite nuts at top; threaded wooden clamp at top to apply pressure to pile.

Condition: good; complete

References

Henry Schmidt; 'Frogs and Animal Electricity'; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge: https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/frogs/frogs-and-animal-electricity

Events

Description
The voltaic pile was discovered in 1796 by Alessandro Volta (1745-1827). Volta was the Professor of physics at the University of Pavia, Italy. The voltaic pile was the first practical battery ever produced and for the first time provided a continuous source of electricity. The volt, which is the unit for electromotive force (the electrical force of a cell or battery which makes electrons flow around a circuit) is named after Volta.

The voltaic pile consisted of plates of copper and zinc which were separated by moistened cloth pads (a cell). The liquid used to moisten the pads in the first voltaic piles was a solution of salt or weak acid such as vinegar. These cells were piled up by Volta to create a battery, which could then produce a flow of electric charge.

The reaction that occurs is called electrochemical. The copper loses electrons into the salt solution whilst the zinc gains electrons from the this solution. At the same time the zinc dissolves and hydrogen gas is produced on the surface of the copper. When the charge flows along wires, the wires separate out more charge, causing the electric charge to continue flowing.

FM:41053