424 Dr. Hare on the Theory of Storms, 



the other hand, if we attribute the ascent of the air at the 

 equator to heat, the theory of calorific circulation will account 

 for the continuance of the process. 



6. In ascribing the prevalence of westerly winds in the 

 upper regions of the atmosphere to the deflection of the trade 

 winds by our mountains, Mr. Redfield's explanation har- 

 monizes with the theory of Halley. In fact, is it not reason- 

 able, that, as the water accumulated by these winds in the 

 Gulf of Mexico is productive of a gulf-stream, there should be 

 an aerial accumulation and current corresponding with that 

 of the aqueous current, which is designated by the name 

 above-mentioned ? 



7. But not perceiving that the trade winds cannot be ex- 

 plained without the agency of temperature, Mr. Redfield, in 

 the following paragraph, rejects the influence of heat : — 



8. " To me it appears that the causes of the great storms 

 may be considered to indicate with entire certainty the great 

 Jaw of circulation in our atmosphere; and that the long- 

 cherished theory, which is founded on calorific rarefaction, 

 must give place to a more natural system of winds and storms, 

 founded mainly upon the more simple conditions of the great 

 laws of gravitation." 



9. It would seem from this paragraph as well as others, that 

 Mr. Redfield admits of no other cause of atmospheric currents 

 besides that of gravitation. But in the absence of calorific 

 and electrical reaction, what other effect could gravitation 

 have, unless that of producing a perfect state of inert quies- 

 cence? 



10. It is remarkable that the author, after ascribing the 

 trade winds to momentum, as the antagonist of gravitation, 

 loses sight of it in this summing up of the causes of atmospheric 

 currents ! 



11. If, as Mr. Redfield alleges, the minuteness of the alti- 

 tude of the atmosphere, when compared with its horizontal 

 extent, be an objection to an}' available currents being induced 

 by calorific rarefaction, wherefore, for the same reason, should 

 not momentum, or any other cause diminishing or counteract- 

 ing the influence of his chosen agent, gravity, be equally in- 

 efficient ? 



12. Assuming that the motion of the air in hurricanes is 

 always gyratory, Mr. Redfield considers gyration as a cause 

 of these terrible meteors ! How far his language on this sub- 

 ject is reasonable or consistent, may be seen from the following 

 paragraph, which I quote from one of his essays, published in 

 Silliman's Journal for 1834, vol. xxv. page 125:— 



13. " Notwithstanding these general and determinate ho- 



