The reverberations, too, of the mountains, and the roaring of the forests, are indicative of certain phænomena; and the same is the case when the leaves are seen to quiver,[1] without a breath of wind, the downy filaments of the poplar or thorn to float in the air, and feathers to skim along the surface of the water.[2] In champaign countries, the storm gives notice of its approach by that peculiar muttering[3] which precedes it; while the murmuring that is heard in the heavens affords us no doubtful presage of what is to come.