Harris Quadrant Electrometer (ca. 1920s)
Early twentieth century quadrant electrometer manufactured by Philip Harris Limited of Birmingham England (ca. 32" high).
This example is remarkably good shape with the exception that the Leyden jar is missing.
A small metal weight can be seen suspended at the end of a wire beneath the vane at the bottom of the case. Normally the weight is immersed in a solution of sulfuric acid inside the small glass Leyden at the bottom. The inside of the mahogany case is lined with tin foil to shield the system from stray electrostatic charges.