178 PHILOSOPHY OF STORMS. 



superincumbent weight of the column of air over the bar- 

 ometer. The cause of this diminished weight has been ex- 

 plained before, and its amount, under given circumstances, 

 has been calculated. If the advocates of the whirlwind doc- 

 trine admit an inward and spiral motion, then the barometer 

 would not fall by the centrifugal action, but rise by the accu- 

 mulation of air above; unless the air above is thrown outwards 

 by a greater centrifugal action above, or in some other way. 

 Thus the grand objection, which they bring against my 

 theory, becomes unanswerable against theirs, unless they 

 can show that the gyrations above are sufficient to throw 

 the air outwards there. This, I say, must be shown ; for 

 it will not do to assume it as a hypothesis. 



137. The velocity with which this storm moved from west 

 to east cannot be ascertained with absolute accuracy, yet a 

 near approximation may be made by the accurate observa- 

 tions, at New Haven, Waterville, Philadelphia and Bur- 

 lington, N. Y. The centre of the storm passed over Phila- 

 delphia at forty minutes past two, P. M., over New Haven 

 about forty minutes past eight, and over Waterville about 

 half past four, on the morning of the 27th. This will give 

 a velocity of motion to the central line of the storm, side 

 foremost, of about sixteen or seventeen miles an hour. 



Now the wind at the surface of the earth, where it is sub- 

 jected to much friction, was blowing in towards the central 

 line with a velocity of double or tripple of the motion of 

 the storm itself. A little above the surface of the earth the 

 velocity of the air inwards would be much greater on ac- 

 count of the friction being less. What an amazing quantity 

 of air rushed towards the central line of this storm, carry- 

 ing with it an ocean of vapor to be condensed, by the cold 

 of diminished pressure as it ascended. 



138. We can even form some rough estimate of the rela- 

 tive quantities which ascended on the different sides of the 

 central line. Much more certainly ascended on the east 



