harvester main frame 11 changes the rotational position of pivot 16 and the attached gathering arm link 88 link 88 moves slotted link 89 either rearwardly or forwardly the movement of link 89 is depending upon whether the harvester wheels sink or elevate fore aft movement of slotted link 89 translates into rotational movement of pivot arm assembly 85 which in turn translates into upward or downward movement of slider assembly 44 which lifts bell crank 32 causing its arms 66 67 to rotate thus operating control valve 70 to control hydraulic fluid flow to hydraulic cylinder 90 lifting or lowering base cutter 12 the table 1 below lists the parts by number and description as used herein and on the drawings table 1______________________________________parts listpart number description______________________________________10 sugar cane harvester11 frame12 basecutter13 gathering arm14 rear end gathering arm15 front end gathering arm16 pivot17 ground level sensor assembly18 slipper19 sensor link arm20 sensor link arm21 sensor link arm22 sensor link arm23 sensor mounting bracket24 sensor lifting mechanism25 chain26 gusset27 opening28 sheave29 sheave housing30 hydraulic cylinder31 pushrod32 bell crank33 openings34 push pull cable35 yoke36 cable protector37 bolted connection40 compensator slider assembly41 fixed vertical rail42 flange43 flange44 compensator slider45 clip46 clip47 bolted connection48 bolted connection49 slot50 gusset51 opening52 hydraulic cylinder53 mounting bracket54 mounting bracket55 bias rail56 bolt57 threaded openings58 rear end cable59 front end cable60 bias slider assembly61 bell crank shaft62 cable support63 bolted connection64 gusset plate member65 bell crank opening66 crank arm67 crank arm68 opening69 opening70 control valve71 toggle72.