21 ELECTRIC RESISTANCE UNITS OR TUBES OR COILS, ELECTRIC RHEOSTATS, ELECTRIC MOTOR STARTERS, ELECTRIC VOLTAGE, CURRENT, AND SPEED REGULATORS, ELECTRIC SWITCHES, ELECTRIC CIRCUIT CONTROLLERS FOR CHANGING CIRCUIT CONNECTIONS IN A PREDETERMINED MANNER AND OTHERWISE, ELECTRIC CURRENT CUTOUTS AND ELECTRO-MAGNETIC CIRCUIT BREAKERS, AND ELECTRIC CONTROLLING PANELS