1. IN A HYDRAULIC CONTROL SYSTEM OF A TYPE INCLUDING A FIRST CONTROL SYSTEM, A HYDRAULIC POWER MEANS DESIGNED FOR OPTIMUM CONTROL BY SAID FIRST CONTROL SYSTEM, AND A SECOND CONTROL SYSTEM HAVING DIFFERENT OPERATING CHARACTERISTICS FROM SAID FIRST CONTROL SYSTEM TO ALTERNATIVELY CONTROL SAID HYDRAULIC POWER MEANS; THE IMPROVEMENT COMPRISING A MOTION CHANGING MEANS OPERATIVELY CONNECTED BETWEEN THE OUTPUT OF THE SECOND CONTROL SYSTEM AND AN INPUT OF THE POWER MEANS TO CORRECT FOR THE DIFFERENT OPERATING CHARACTERISTICS OF SAID SECOND CONTROL SYSTEM WHEREBY OPTIMUM CONTROL OF THE HYDRAULIC POWER MEANS MAY BE EFFECTED BY SAID SECOND CONTROL SYSTEM, SAID MOTION CHANGING MEANS INCLUDING A HOUSING MEANS SLIDABLY MOUNTED IN THE HOUSING AND CONTROLLED BY THE SECOND SYSTEM, A PLATE RIGIDLY ATTACHED ON THE HOUSING AND HAVING A CAM SURFACE AND A CHANNEL, A CAM FOLLOWER ROLLER MOUNTED IN THE CHANNEL FOR TRAVELING THEREIN AN MAKING CONTACT WITH THE CAM SURFACE, A CAM FOLLOWER LEVER PIVOTALLY CONNECTED AT A POINT TO SAID CAM FOLLOWER ROLLER, A ROD LONGITUDINALLY POSITIONED BY SAID OPERATIVE MEANS, SAID ROD BEING SLIDABLY MOUNTED WITH RESPECT TO THE HOUSING AND PIVOTALLY CONNECTED TO SAID CAM FOLLOWER LEVER AT ANOTHER POINT, AND LINKAGE OPERATIVELY CONNECTED TO THE INPUT OF THE HYDRAULIC POWER MEANS, SAID OPERATIVE LINKAGE BEING PIVOTALLY CONNECTED TO SAID CAM FOLLOWER LEVER AT STILL ANOTHER POINT, SO THAT LONGITUDINAL MOVEMENT OF THE ROD BY SAID OPERATIVE MEANS ANGULARLY POSITIONS SAID CAM FOLLOWER LEVER RELATIVE TO THE CHANNEL TO VARY THE POSITION OF THE OPERATIVE LINKAGE IN COOPERATIVE RELATION THEREWITH TO CORRECT FOR THE DIFFERENT OPERATING CHARACTERISTICS OF SAID SECOND CONTROL SYSTEM WHEREBY OPTIMUM CONTROL OF THE HYDRAULIC POWER MEANS MAY BE EFFECTED BY SAID SECOND CONTROL SYSTEM.