Downing's Improved Battery

Downing's Improved Battery is a electro-therapeutic medical medallion in the shape of a horse-shoe, patented in Canada on 13 October 1881, by Joseph M. Downing,, and sold through Downing Electric Co.

Design
The design of Downing's Battery is described as "composed of a copper ring surrounding a central zinc disc, said copper ring having radial arms, the spaces between which are filled up with zinc annular sections, and the whole enclosed within a horse-shoe rim."