four o'clock
For every yard gained seven had to be travelled . It was not a march , it was a battle ; a battle without rest and without end and without mercy ; a battle with an Enemy whose power was beyond all estimate and whose movements were not reducible to any known law . A certain course would be mapped , certain plans formed , a certain objective determined , and before the course could be finished , the plans executed , or the objective point attained the perverse , inexplicable movement of the ice baffled their determination and set at naught their best ingenuity . At four o'clock it began to snow . Since the middle of the forenoon the horizon had been obscured by clouds and mist so that no observation for position could be taken . Steadily the clouds had advanced , and by four o'clock the expedition found itself enveloped by wind and driving snow . The flags could no longer be distinguished ; thin and treacherous ice was concealed under drifts ; the dogs floundered helplessly ; the men could scarcely open their eyes against the wind and fine , powder-like snow , and at times when they came to drag forward the last sledge they found it so nearly buried in the snow that it must be dug out before it could be moved .