The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Crookes & Geissler Tube Assortment I can hardly believe these were repaired tubes.  Lutz is amazing. Frank has some magic for his collection here! Beautiful Crookes Butterfly Tube Low Pressure Tube Catherine's Wheel Tube Fantasy Violet Ray Electrodes with Geissler Shapes.  Ingenious!