1. IN A ROPE TOW, A SET OF SHEAVES INCLUDING TWO PAIRS OF GUIDE SHEAVES ONE PAIR FOR THE UP-HILL AND ONE PAIR FOR THE DOWN-HILL END OF A SKI SLOPE, INDIVIDUALLY MOUNTINGS PROVIDING ROTARY JOURNALS FOR THE TWO GUIDE SHEAVES OF EACH PAIR AND PLACING THE TWO SHEAVES ONE ABOVE ANOTHER IN LONGITUDINAL VERTICAL PLANES WHICH GENERALLY CONCIDE, AN ENDLESS POWER-DRIVEN TOW ROPE OF THE TWISTED CHARACTER TRAINED OVER SAID SET OF SHEAVES AND IN ITS TRAVEL OVER THE GUIDE SHEAVES TRACING A GENERALLY RECTANGULAR COURSE FIRST WORKING DOWNWARDLY FROM THE UPPER TO THE LOWER SHEAVE OF THE DOWN-HILL PAIR, THENCE PROGRESSING ON A LOWER-LEVEL TOW RUN TO THE LOWER SHEAVE OF THE UP-HILL PAIR, AND THEN WORKING UPWARDLY TO THE UPPER SHEAVE OF SAID UP-HILL PAIR BEFORE MAKING AN UPPER-LEVEL RETURN RUN, THE MOUNTINGS FOR AT LEAST THE LOWER SHEAVES IN SAID TWO PAIRS OF GUIDE SHEAVES BEING EACH CARRIED FOR ADJUSTING SWIVEL MOTION ABOUT A RESPECTIVE HORIZONTAL AXIS LOCATED NORMAL TO THE CONCERNED JOURNAL AXIS, AND MEANS FOR SETTING SAID ADJUSTABLE MOUNTINGS AT SELECTED POINTS WITHIN A PERMITTED RANGE OF SWIVEL MOTION.