104 PROCEEDINGS OF THE AMERICAN ACADEMY 



" I took Professor Espy to view the ground soon after the tornado 

 had passed, who drew my attention to the position of trees that were 

 prostrated, and which lay with their tops turned inward and forward. 

 He explained this in accordance with his published theory, which 

 maintains that the dynamic effects upon the trees are of two kinds, — 

 one resulting from the inward and vertical attraction, produced by a 

 vacuum in the cloud, drawing the trees inward toward the cone, and 

 upward, and uprooting them ; the other, from its progressive course, 

 which fells them with their tops for<vard. He states in his book that 

 in nine spouts he has visited in New Jersey, the trees and corn all ex- 

 hibited an inward and forward direction. He attaches less impor- 

 tance to the gyratory motion than Read, Redfield, and others have 

 done, and believes it to be accidental. And Dr. A. D. Bache, of Phil- 

 adelphia, who accompanied Professor Espy in some of his examina- 

 tions of the traces of a spout, says : — 'I think it made out that there 

 was a rush of air from all directions, at the surface of the ground, to- 

 ward the moving meteor, this rush of air carrying objects with it. 

 The effects all indicate a moving column of rarefied air, without any 

 whirling motion near the surface of the earth.' In support of the same 

 opinion, I may mention that the roofs of the barns and the wagons in 

 the Providence tornado were lifted upwards, and carried along in a 

 straight line, without being whirled round. Although the electrical ef- 

 fects attendant upon water-spouts and whirlwinds prove that they are 

 closely connected with atmospheric electricity, yet no theory has been 

 advanced that satisfactorily explains all the phenomena. Peltier has 

 given the most rational exposition of the modus operandi of electri- 

 city of any writer I have met with. He has attempted to illustrate it 

 by artificial means and experiments, and with apparent success. On 

 this point Espy differs from him, in referring the dynamic effects of 

 spouts chiefly, if not wholly, to a vacuum in the cloud, which he seems 

 to believe may exist independently of electricity. It is, however, im- 

 probable that any rush of air, unaided by electricity, can produce a 

 drying up of the leaves and of the sap in a tree. The electric fluid, 

 moreover, is often seen darting through such meteors, as was the case 

 in the spout now described." 



Professor Edward Salisbury, of Yale College, and Dr. J. 

 Mason Warren, were elected Fellows of the Academy. 



