"The intensity of the heat may be judged, and the thorough combustion of everything wooden may be understood, when we state that in the yard of one of the large agricultural-implement factories was stacked some hundreds of tons of pig-iron. This iron was two hundred feet from any building. To the south of it was the river, one hundred and fifty feet wide. No large building but the factory was in the immediate vicinity of the fire. Yet, so great was the heat, that _this pile of iron melted and run, and is now in one large and nearly solid mass_."[3] The amount of property destroyed was estimated by Mayor Medill at one hundred and fifty million dollars; and the number of people rendered houseless, at one hundred and twenty-five thousand. Several hundred lives were lost. All this brings before our eyes vividly the condition of things when the comet struck the earth; when conflagrations spread over wide areas; when human beings were consumed by the million; when their works were obliterated, and the remnants of the multitude fled before the rushing flames, filled with unutterable consternation; [1. "History of the Chicago Fire," p. 87. 2. Ibid., p. 119. 3. Ibid., p. 121.] {p. 423} and as they jumped pell-mell into wells, so we have seen them in Job clambering down ropes into the narrow-mouthed, bottomless pit. Who shall say how often the characteristics of our atmosphere have been affected by accessions from extraterrestrial sources, resulting in conflagrations or pestilences, in failures of crops, and in famines? Who shall say how far great revolutions and wars and other perturbations of humanity have been due to similar modifications? There is a world of philosophy in that curious story, "Dr. Ox's Hobby," wherein we are told how he changed the mental traits of a village of Hollanders by increasing the amount of oxygen in the air they breathed. {p. 424} CHAPTER VI. THE UNIVERSAL BELIEF OF MANKIND. THERE are some thoughts and opinions which we seem to take by inheritance; we imbibe them with our mothers' milk; they are in our blood; they are received insensibly in childhood. We have seen the folk-lore of the nations, passing through the endless and continuous generation of children, unchanged from the remotest ages. In the same way there is an untaught but universal feeling which makes all mankind regard comets with fear and trembling, and which unites all races of men in a universal belief that some day the world will be destroyed by fire.