The sky, hitherto bright, became overcast with clouds about the time that we had got over about two-thirds of the day's journey.  Hugh and Red Squirrel and I were at some distance in the rear of the party, when snow began to fall and the wind to blow with unusual violence.  The snow came down so thickly that it seemed as if the contents of a huge feather-bed had suddenly been emptied upon us.  Thicker and thicker it fell; so great was the obscurity that we could scarcely see a yard ahead, while the tracks of our companions were almost instantly obliterated.