Proximate Causes of certain Winds and Storms. 261 



own course. These obscure and erroneous views of the nature of 

 that motion of the air, which constitutes wind, seem to pervade most 

 of the meteorological speculations of an individual holding a high 

 rank amongst the philosophers of the age — Mr. Leslie, of Edinburgh. 

 See his investigation of the causes of the oscillations of the mercury 

 in the barometer, and his illustrations of the Huttonian theory of 

 rain — [that it is produced hy the mingling of air of different tempe- 

 ratures, charged with moisture) referred to by Playfair, (Outlines, 

 Vol. i, p. 316) with approbation, as containing a correct exhibition 

 of the rationale of falling weather. 



" To explain the actual phenomena, we must have recourse to the 

 mutual operation of a chill and of a warm current, driving swiftly in 

 opposite directions, and continually mixing and changing their conter- 

 minous surfaces.* (Leslie on heat and moisture, p. 139.) 



If the two currents come from opposite directions, the motion of 

 both will be destroyed, or one will drive the other back before it, 

 along its former track. In eidier case, tliere will be a mixture of 



*This passage appears a second time, without any alteration of the language in 

 the article Meteorology, drawn up by the same author, for the Supplement to the 

 Encyclopedia Brittanica, ten years after the publication of the account of experi- 

 ments respecting heat and moisture, so that he seems to regard this theory either as 

 not admitting of, or not requiring any correction or improvement. In the fifteenth 

 Volume of this Journal, at page 12, is an "Hypothesis on Volcanoes and Earth- 

 quakes, by Joseph Du Commun, of the Military Academy at West Point." It has 

 the stamp of originality, and no one who reads it over, will doubt that it is the result 

 of the unaided operations of his own mind ; but if the author of that paper will ex- 

 amine this article of Leslie's, in the Encyclopedia, he will find that he has been anti- 

 cipated in all the points of his hypothesis. Indeed, if the writer who furnished an 

 analysis, with critical remarks of Professor Leslie's speculations for Brando's Jour- 

 nal, is to be believed, it did not originate with him, but with an individual whom we 

 should hardly expect to find engaging m this kind of speculation — Dr. Southey, the 

 PoetLaui-eate. 



" We think tliis the wildest conceit that ha.i ever figured in a sober work on phi- 

 losophy. It throws Bishop Willdns' schemes quite into the shade, and seems to ri- 

 val some of Mr. Southey's oriental fictions, from one of which, the Doundaniel cav- 

 ern, it is manifestly borrowed. We shall not consume our reader's time with a se- 

 rious refutation of this shower of atmospheric air drops, pushing themselves down the 

 watery abyss, from five and a half miles beneath the surface to the very bottom. 

 Nor shall we alarm their fears for the respiration of posterity, when this unceasing 

 operation shall have smuggled the whole atmosphere into its submarine vaults. We 

 shall merely congratulate old Ocean on the possession of this soft, elastic and self- 

 adjusting pillow. To complete this new Neptunian theory, Mr. Leslie should have 

 shewn how, when this pillow becomes over-stufted, the surplus air could be squeez- 

 ed out, as occasion required, through one of Pluto's spiracles, to inflate the bellows 

 of the Cyclops." Journal for October, 1822, pages 177—5. . 



Vol. XIX.— No. 2. 34 



