It is important to inquire whether the southerly drift which stopped Parry was due to northerly winds or to a southerly current; and if to the latter cause, whether this current probably affects the whole extent of the sea in which Parry’s ice-field was drifting. We know that his party were exposed, during the greater part of their advance from Spitzbergen, to northerly winds. Now the real velocity of these winds must have been greater than their apparent velocity, because the ice-field was moving southwards. Had this not been the case, or had the ice-field been suddenly stopped, the wind would have seemed stronger; precisely as it seems stronger to passengers on board a sailing vessel when, after being before the wind for a time, she is brought across the wind. The ice-field was clearly travelling before the wind, but not nearly so fast as the wind; and therefore there is good reason for believing that the motion of the ice-field was due to the wind alone. If we suppose this to have been really the case, then, as there is no reason for believing that northerly winds prevail uniformly in the Arctic regions, we must regard Parry’s defeat as due to mischance. Another explorer might have southerly instead of northerly winds, and so might be assisted instead of impeded in his advance towards the Pole. Had this been Parry’s fortune, or even if the winds had proved neutral, he would have approached nearer to the Pole than Nares. For Parry reckoned that he had lost more than a hundred miles by the southerly drift of the ice-field, by which amount at least he would have advanced further north. But that was not all; for there can be little doubt that he would have continued his efforts longer but for the Sisyphæan nature of the struggle. It is true he was nearer home when he turned back than he would have been but for the drift, and one of his reasons for turning back was the consideration of the distance which his men had to travel in returning. But he was chiefly influenced (so far as the return journey was concerned) by the danger caused by the movable nature of the ice-field, which might at any time begin to travel northwards, or eastwards, or westwards.