SCIENCE PHOTO LIBRARY SCIENCE PHOTO LIBRARY
Gold leaf electrometer. This is an instrument for measuring static charges. If a rod charged with static electricity is brought near the terminal of an electroscope, the plate becomes charged by static induction, and the charge passes down into the electroscope itself. There, a hinged gold leaf (seen here at rest) also becomes charged and is repelled by the vertical metal plate. The amount of charge can be read from the scale.
Model release not required. Property release not required.