ratio output gear 180 the low ratio input gear 190 the high ratio output gear 200 and the high ratio input gear 210 as depicted in exemplary fashion in fig1 and 2 causes the low ratio second stage input half shaft 140 to rotate at a lower speed than the high ratio second stage input half shaft 150 the second stage differential gear 160 aggregates the power from the first pathway and the second pathway and outputs rotational energy on the second stage output shaft 170 as a load is placed on the second stage output shaft 170 the transmission of the present invention will automatically respond by aggregating the power from the first and second pathways in varying proportions to produce an output on the second stage output shaft 170 having an optimum torque value for turning the machine no control mechanism is necessary to achieve the selection of the optimum torque output a relatively large load on the second stage output shaft 170 may cause the second stage differential gear 160 to reverse the direction of rotation on the high ratio second stage input half shaft 150 and thereby reverse the direction of power transfer over the second pathway for this reason it is preferred that the second pathway include means for preventing reversal of power on the second pathway fig1 and 2 depict an embodiment of the present invention having means for preventing reversal namely a ratchet bearing 220 of conventional design installed on the high ratio first stage output half shaft 60 for preventing reverse rotation in the second pathway alternatively the.