The storm itself was one of those which come but seldom. Nature's mighty forces flung loose in one giant cataclysm. It came from the north, and it had a full sweep down the valley of the Hudson, pent in and focused to one point by the mountains on each side. It tore the trees from the tops as it came; it struck the river with a swish, and beat the water into foam. It flung the raindrops in gusts against it, and caught them up in spray and whirled them on; and this, to the echoing crashes of the thunder and the dull, lurid gleam of the lightning that played in the rear.