with reference to the Views of Mr. Redfield. 425 



rizontal movements, the equal distribution of the atmosphere 

 over the surface of the globe,which results from gravitation, 

 tends to prevent any very rapid or violent motion in any spe- 

 cific direction, and consequently to prevent violent and de- 

 structive winds. But owing to the tendency of all fluid matter 

 to run into whirls or circuits, when subject to the influence of 

 unequal or opposing forces, a rotative movement of unmea- 

 sured violence is sometimes produced. This peculiar move- 

 ment, which in its most active state is sometimes distinguished 

 by the name of tornado or hurricane, assumes every possible 

 vai'iety of position, appearance, velocity and extent, and is 

 the only known cause of violent and destructive winds or 

 tempests." 



14. Agreeably to this paragraph, gravitation, in lieu of being, 

 as previously alleged, the main basis of winds and storms, 

 tends to produce that equal distribution of the atmosphere 

 over the surface of the globe, on which I have insisted. 



15. But if neither gravity, nor calorific expansion, nor elec- 

 tricity be the cause of winds, by what are they produced? 



16. He alleges that the fluid matter has a tendency to run 

 into whirls or circuits, when subject to the influence of un- 

 equal or opposing forces, and that in this way a rotative 

 movement of unmeasured violence is sometimes produced. 



17. If this were true, evidently whirlpools, or vortices of 

 some kind, ought to be as frequent in the ocean, as, agreeably 

 to his observation, they are found to be in the atmosphere. 

 The aquatic gulf-stream, resulting from the impetus of the 

 trade winds, ought to produce as many vortices in its course 

 as the aerial currents derived from the same source, especially 

 as in the ocean the great laws of gravitation have full liberty to 

 act without any important interference from calorific changes, 

 to which the advocates of the agency of such changes in pro- 

 ducing wind will not ascribe much efficacy, where non-elastic 

 liquids are in question. 



18. There are few vortices or whirlpools in the ocean, be- 

 cause there are in few cases descending currents towards which 

 the surrounding waters are concentrated. Of course, vertical 

 currents cannot arise from any imaginable cause. 



19. The conflicts of "opposing or unequal forces" do not 

 produce curvilinear motion, unless there be a successive de- 

 flection, as in the case where it results from centripetal force, 

 or the influence of gravity upon a projectile. If one of two 

 directly opposite forces be less than the other, retardation will 

 ensue, and a lateral current or currents carrying off the excess 

 of momentum. If currents encounter each other obliquely, 

 a diagonal current will result, I doubt if a whirlpool ever 



