with mains operated transformer 

Coil mains operated or wet battery for spark in air or discharge Coils consist of enameled copper wire wound on a solenoid. Ruhmkorff commentator allows primary current to be bath reversed and switched on and off. Metal discharge electrodes with Bakelite handles insulated, perspex sheets Complete assembly is mounted on a wooden base with ON/OFF

For use with Geissler tubes, spectrum analysis tubes, or various cathode tubes for demonstrates of high voltage characteristics.