^ Tornado in N. E. part of Ohio, Feb. A, 1842. 293 



at Kirtland had a tight ceiling of plaster, without any opening to 

 the garret ; so that currents of air which might find their way 

 into the building might strike tipon this ceiling, but would be ef- 

 fectually cul off from the roof. The ceiling was uninjured, but a 

 large hole burst in the roof. The reason then assigned, though 

 admitted to be a vera causa, is wholly inadequate to explain the 

 phenomenon. I ascribe it to a rarefaction of the air. A current 

 of air forcibly impelled over an obstacle like the roof of a build- 

 ing, by friction drags along with it the air lying upon the leeward 

 side of the roof, producing a partial rarefaction which might ea- 

 sily be sufficient to lift the roof. The degree of rarefaction requi- 

 site to produce the effect is much less than some might imagine. 

 Suppose a barometer above the roof to stand only one tenth of an 

 inch lower than within the building, we have an upward force 

 of seven pounds per square foot, a force probably sufficient to 

 throw off a considerable part of the barn roofs of Ohio. 



In the tornado which occurred at Stow in 1837, a circumstance 

 was remarked which I had never seen noticed before, that several 

 fowls were picked almost clean of their feathers. In the New 

 Haven tornado of 1839, the same fact was noticed. I made par- 

 ticular inquiry on this point at Mayfield. Four geese were found 

 near Mr. Dean's house lying dead among the rubbish, without any 

 perceptible loss of feathers. I heard of one goose so far stripped 

 that its remaining feathers were not considered worth saving : its 

 legs and wings were both broken. A turkey also was found 

 lodged in a tree near Dean's, with the loss of about half of its 

 feathers, and its bones broken. As electricity has been maintain- 

 ed to be the efficient cause of tornadoes, I have inquired whether 

 this loss of feathers could be due to electric repulsion. I 

 think not — Because first, the effect is not uniform ; many fowls 

 near the centre of the Mayfield tornado were killed but did not 

 lose their feathers. Secondly, although electricity was manifest- 

 ed in the passage of the tornado, its intensity did not appear to, 

 be equal to that of a common summer thunder-shower. Thirdly, 

 the effect may be explained by other causes known to be in ope- 

 ration. The gun mentioned on p. 284, was charged with five 

 ounces of powder, and a chicken just killed added for a ball. 

 As the gun was small, it was necessary to press down the chick- 

 en with considerable force, by which means it was probably some- 

 what bruised. The gun was pointed vertically upwards and 



