1. IN A LABEL FORMING DEVICE FOR FORMING INDIVIDUAL LABELS FROM A CONTINUOUS STRIP OF PRINTED LABELS COMPRISING A FRAME, A FEED ROLL ON SAID FRAME, DRIVE MEANS OPERATIVELY CONNECTED TO SAID FEED ROLL FOR CONTINUOUS ROTATION OF SAID FEED ROLL AT SELECTIVELY VARIABLE SPEEDS, A SUPPLY ROLL SUPPORTING SHAFT ON SAID FRAME, SAID SHAFT BEING CONSTRUCTED TO RELEASABLY SUPPORT A SUPPLY ROLL HAVING A CONTINUOUS STRIP WOUND THEREON, SAID SHAFT ALSO ROCKABLY SUPPORTING A CONTROL ARM, SAID CONTROL ARM HAVING AN IDLER ROLL AT ONE END AND A MERCURY SWITCH INTERMEDIATE ITS ENDS, SAID MERCURY SWITCH BEING MOUNTED ON A FINGER WHICH IS ITSELF PIVOTALLY CONNECTED TO SAID CONTROL ARM, A TRANSVERSE BRACKET ON SAID FINGER, A LATERAL FLANGE ON EACH OF THE OPPOSITE ENDS OF SAID BRACKET, A PAIR OF STOPS ON SAID FRAME, SAID STOPS BEING ON OPPOSITE SIDES OF SAID CONTROL ARM AND IN A POSITION WHERE THEY MAY BE ENGAGED BY AN ABUTMENT MEANS ON SAID FINGER UPON CORRESPONDING ROCKING MOVEMENT OF SAID CONTROL ARM, AND A SPRING ON SAID ARM, SAID SPRING BEING IN ENGAGEMENT WITH SAID FINGER AND EXERTING A FORCE RADIAL TO THE PIVOT OF SAID FINGER WHEREBY IT ACTS TO SNAP SAID FINGER INTO OPPOSITE PIVOTED POSITIONS UPON MOVEMENT OF SAID FINGER BEYOND ITS DEAD CENTER POSITION IN EITHER DIRECTION, SAID MERCURY SWITCH BEING IN ELECTRICAL CIRCUIT WITH A SOLENOID, SAID DRIVE MEANS BEING OPERATIVELY CONNECTED TO TWO SETS OF GEARS, ONE OF SAID SETS OF GEARS BEING CONSTRUCTED AND ARRANGED TO DRIVE SAID FEED ROLL RELATIVELY SLOW AND THE OTHER OF SAID SETS OF GEARS BEING CONSTRUCTED AND ARRANGED TO DRIVE SAID FEEL ROLL RELATIVELY FAST, A CLUTCH MEANS TO SELECTIVELY AND ALTERNATIVELY ENGAGE AND DISENGAGE SAID SETS OF GEARS TO AND FROM OPERATIVE CONNECTION WITH SAID DRIVE MEANS, SAID SOLENOID HAVING A PLUNGER IN OPERATIVE CONNECTION WITH SAID CLUTCH MEANS, AND SAID PLUNGER BEING ACTUATED INTO CLUTCH ENGAGING AND DISENGAGING POSITIONS BY MOVEMENT OF SAID CONTROL ARM AND THE MERCURY SWITCH THEREON.