452 PHILOSOPHY OF STORMS. 



authority of Marshall Hall and Mr. Varley in his favor on 

 this point, Mr. Hall says : " The transition of atmospheric 

 moisture from the elastic to the fluid state, must be attended 

 by a diminution of bulk and elasticity, and consequently 

 by a movement in the adjacent regions of the atmosphere 

 and by a fall of the barometer.' 3 [Jour. Science and the 

 Arts, vol. xx., p. 20.] 



Mr. Varley endeavors to show, in correspondence with 

 what he frequently sees, that storms of lightning will 

 always occasion a current of wind from the external re- 

 gions towards itself. Hence a dead calm preceding a storm, 

 and a fall of the barometer, as this is the focus of conden- 

 sation. [Vol. xxxiv. p. 162, of Tilloch's Mag.] 



In conclusion, it is not a little remarkable that, in ad- 

 vocating the whirlwind character of the tornado, the Pro- 

 fessor took no notice of a " test/' laid down by Mr. Red- 

 field, in the following words : 



"If the traces or prostrations in the paths of tornadoes 

 be the eifects of a wind blowing from all sides directly 

 towards the centre of the tornado, then the predominant 

 effects of the wind in the centre of its path, will be found 

 parallel to its course ; but if the effects here, be transverse 

 to the line of progress, then the prostration was occasioned 

 by a whirlwind; no matter in which of the transverse, or 

 longitudinal directions, the effects may have been pro- 

 duced." 



This test I had accepted as a true one ; and Pro- 

 fessor Olmsted had already published to the world, that 

 " near the centre of the New Haven tornado, the direction of 

 prostrate bodies is coincident with that of the storm." If 

 Professor Olmsted is " blind to evidence" furnished by him- 

 self, which Mr. Redfield says would satisfy him of the 

 truth of my theory, then must I despair of ever making 

 him a convert to my theory. I appeal to the unprejudiced. 



