Page:Popular Science Monthly Volume 2.djvu/218

From Wikisource
Jump to: navigation, search
This page has been validated.
206
THE POPULAR SCIENCE MONTHLY.

earth's internal forces may be as active now as in the epochs when the mountain-ranges were formed. But Mr. Mallet's theory tends to show that the volcanic energy of the earth is a declining force. Its chief action had already been exerted when mountains began to be formed; what remains now is but the minutest fraction of the volcanic energy of the mountain-forming era; and each year, as the earth parts with more and more of its internal heat, the sources of her subterranean energy are more and more exhausted. The thought once entertained by astronomers, that the earth might explode like a bomb, her scattered fragments producing a ring of bodies resembling the zone of asteroids, seems further than ever from probability; if ever there was any danger of such a catastrophe, the danger has long since passed away.—Spectator.

 

GREAT FIRES AND RAIN-STORMS.

ASSISTANT PROFESSOR OF PHYSICS 1ST HARVARD COLLEGE.

THE belief that great fires are followed invariably by rain-storms is wide-spread, and the great fires of the present year in America, it is claimed, afford no exception to the law. The attitude of scientific men in regard to so-called popular fallacies and superstitions is not, in general, a praiseworthy one. A belief needs often only to be widespread among the people at large to be denounced. Science is but another word for truth, and even popular traditions deserve to be examined with care. The difficulties, however, in the way of an investigation of the effects of fires in producing rain-storms are manifold. Our knowledge of the science of meteorology is, at the best, very imperfect; and we have no series of observations from which we can draw trustworthy conclusions. A careful search into the narratives of great fires and into the accounts of great naval and land fights gives nothing which a scientific man would accept for a moment. One who is ready and determined to believe, it is true, will find in history many curious and apparent corroborations of the truth of his belief. Thus in Pepys's "Diary" there is a quaint and circumstantial account of the great fire in London. In speaking of the progress of the fire, he says: "So as we were forced to begin to pack up our own goods, and prepare for their removal; and did by moonshine (it being brave dry and moonshine and warm weather) carry much of my goods into the garden;" and in another place: "But Lord! what a sad sight it was by moonlight to see the whole city almost on fire that you might see it plain at Woolwich, as if you were by it." In still another place, in speaking of the poor sufferers made homeless by the fire: "A great blessing it is to them that it is fair weather for them to keep abroad night and day." He thus