The author of the present study prefaces his essay with a few general considerations upon the advances made in meteorology, especially in the study of the mechanics of the atmosphere, which is now coming to the front. Sailors will be the first to benefit by this movement of opinion; meteorology has invariably awakened in them a powerful interest, and this is only natural. "When one spends half of a lifetime upon the deck of a ship continually moving about, one meets the same phenomenon under so many different aspects that he cannot help asking himself what the determinative principle is." (Admiral Mottez.) The writer further states that his efforts have been directed to establishing upon a firm basis the conclusions that terminate his work and form its quintessence, so to speak.
NATURE OF THE AIR—THE ATMOSPHERE.