Electroscope. 19th-century artwork showing designs of an electroscope, a device that detects and records the presence of static electricity, here by deflection of needles on the gauges. This electroscope design was constructed in Paris by French instrument makers Eugene Ducretet (1844-1915) and L. Lejeune. Artwork from the first volume (1897) of 'La Revue Scientifique et Industrielle' by French chemist and inventor Jules-Louis Breton (1872-1940).