434 PHILOSOPHY OF STORMS. 



brought forward as conclusive against my theory, was one 

 of irresistible power in its favor. And 1 think we may 

 safely conclude, it was satisfactory to Professor Olmsted him- 

 self, as it was not attempted to be impugned ; though it was 

 one which I dared my opponents to attempt to invalidate. 



It is true the Professor said, "my chimney would not draw 

 because the bricks were all out ;" that is, even if the cloud is 

 as much lighter than the surrounding air, as I say it is, 

 still the air would not run in below and upwards in the 

 middle and outwards above. This being contrary to the 

 known laws of dynamics, and to the doctrine taught in all 

 the books, that air which is rarefied by heat will ascend and 

 other air rush in to take its place, or rather press it up by 

 its superior gravity, I suppose it was intended for wit and 

 not for argument, and as such needs no answer from me. I 

 will only say the Professor's figure of a narrow streamlet or 

 cylinder of air, confined to a very narrow space under the 

 centre of the cloud, did not convey a correct idea of the 

 doctrine which I teach, namely, that the air flows in on all 

 sides, sloping upwards from beyond the borders of the 

 cloud, not only at the surface of the earth, but up to the 

 base of the cloud itself, and sometimes a little above, when 

 the cloud becomes of great perpendicular altitude, from its 

 summit to its base, as is then manifested by the lower parts of 

 the cloud gathering in on all sides towards the centre. (175.) 



But if the Professor had made his figure to represent this 

 view of the subject, the wit would have disappeared. 



" All new theories," says the Professor, " from Symmes's 

 down, explain some phenomena ; and this imposes on per- 

 sons not scientific. My theory, he says, does not explain 

 all, and therefore is not the true one. For example tor- 

 nadoes sometimes commence in the night, when the air is 

 cooled by contact with the surface of the earth, and there- 

 fore can have no tendency to ascend in columns, but rather 

 to lie still from its superior iveighL And even in the day, 



