The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Experimental Pancake Coil for Brush Discharges Winding pancake coil... 500 turns Coil embedded in paraffin wax / boiled linseed oil / kerosene mixture placed above primary coil from Thomas Stanley Curtis Reproduction Large volume of violet brush discharges, sparks are roughly the same length and colour Mejla Sumo, Ju A similar but earlier spark gap diathermy Prostate Electrode