"Then," said Bainbridge, "we have brought within the limits of reason thirty-five of the fifty feet, and fifteen feet remain to be accounted for. Now let us recall to your memory the fact that the edge of the abyss toward which he leaped was twelve feet lower than the edge from which he sprung; and that, in his progress across the chasm he fell, in addition to this twelve feet, his own height--which, according to Pym's diary was, at that period, four feet and eight inches. If Peters could have covered thirty-five feet on level ground, could he have covered fifty feet with the advantage of a drop of nearly seventeen feet? Assuming a certain weight for Peters, we could calculate the number of foot-pounds of energy, or the initial velocity, necessary to make a leap of thirty-five feet on level ground, and how many foot-pounds it would require to make a leap of fifty feet with a drop of sixteen feet and eight inches taken into the conditions. But as most of the equations in our calculation are approximative, I prefer that the element of gravitation should be handled in a general way. If a leaper were to impel himself horizontally only, he would, in the shortest leap, fall below a level. This fall may be met to the extent of about two feet, by drawing up the legs--that is, by 'hunkering' as the leap progresses, and alighting on his feet with the body to that extent lower than when the spring began. In a leap of twenty-five feet, however, the leaper is compelled to project himself upward as well as forward; and an instinctive sense of just how little energy may be expended in raising himself, and how much may be left for the forward impulse, is one of the chief elements of his proficiency. Peters did not have to raise his body at all." "I begin to comprehend," said I. "Yes," replied Bainbridge, "the more you think of it, the more convinced will you become that Peters made the leap as he states. Of course he could not have sprung fifty feet, or even forty feet, on a level; for, in a leap of only forty feet, one would have to raise himself more than twelve feet into the air, and (except for a possible small advantage of position in leaping) it requires the same amount of force to raise a body ten feet on an incline, as it does to raise the same body ten feet perpendicularly into space--an impossible feat, even to Peters at twenty-eight or thirty years of age." "I quite believe that he did it," I said, "and when we consider that he claims to have measured the distance only mentally, and that he might therefore honestly have mistaken it to the extent of a few feet, I am willing to say that my confidence in his intended veracity is unshaken--even if he is an old sailor."