first: the mariner, when drawing nigh the coasts of foreign lands, if by night he hear the roar of breakers, starts to vigilance, and feels just enough of trepidation to sharpen all his faculties; but under precisely similar circumstances, let him be called from his hammock to view his ship sailing through a midnight sea of milky whiteness—as if from encircling headlands shoals of combed white bears were swimming round him, then he feels a silent, superstitious dread; the shrouded phantom of the whitened waters is horrible to him as a real ghost; in vain the lead assures him he is still off soundings; heart and helm they both go down; he never rests till blue water is under him again.