Unsuspecting souls were they, and yet wholly like other men. Those long resident by the volcano have ceased to fear its fires. Familiarity, even with danger, breeds contempt. The evil which still delays, we fondly believe will never come. And as to the consequences, if those who build dams know so little, why should simple townsmen be expected to know more? Had they guaged that reservoir, and did they know that up there in the mountains were six hundred and forty millions of cubic feet of water, enough to make a veritable Niagara, for more than half an hour, ready to rush down upon them? Had they calculated the awful energy of twenty millions of tons of water falling four hundred and fifty feet in a progress of a dozen miles; and this progress down a pent-up valley, in some places not more than three hundred feet in width? Had they considered that the flow of a mountain of water, sixty feet high at starting, must be far more rapid on the top than at the bottom? That the base, entangled among obstructions, and overspreading them, would furnish to the water above, an inclined plane, smooth as glass, along which it would shoot with the speed of an arrow, to fall over the edge of the retarded water beneath, and furnish in its turn a ready passage for the water above and behind? That in consequence of this law, the flood would come not by a gradual rise, giving time for escape, but like a rolling mountain, to smite with the impact of a falling asteroid, and crush in an instant everything in its way? Had they reflected that such a body of water would outrun the swiftest Paul Revere who might mount steed to fly with the warning to the towns below? That to the doomed, the first announcement of danger would be the stroke of the destroyer? That to the living there would be absolutely no more time for flight than to the sinner, of preparation for judgment after Gabriel shall have blown his trumpet? It is safe to say that few, if any, had even remotely conceived the possibilities in the case. Men learn by experience, and even from experience they fail to learn; for the lesson of to-day is forgotten to-morrow: and human heedlessness is perpetual.