The blizzard is a storm characteristic of the plains. It generally lasts
three days, is terribly cold, and the whirling snow is blinding.
=4.= Black blindness grew white blindness
Indicating the slight difference between night and day.
Note in how few lines the poet pictures the passing of the day.
=5.= All being now seemed narrowed to a span, etc.
All else was shut from sight and to a degree from the mind.