WATER SPOUTS AND WHIRLWINDS. 



575 



bodies, oppositely electrified, are attracted and raised toward the cloud ; when 

 their electricity is neutralized they fall again upon the earth, where, hcinj 

 once more charged with electricity, they reascend, and so on. It is thus th:it 

 an immense cloud of dust is formed under the cone. If the bodies are attached 

 to the earth, like trees or buildi.igs, they are instantaneously charged with an 

 immense quantity of electricity. The earth, which is contiguous to them, par- 

 takes of this electricity, yields to the attraction of the cloud, and the trees, 

 buildings, or other objects upon it, are torn up and transported afar. It is in 

 this manner that bodies which are strongly attached to the earth are torn from 

 it, while others in their immediate neighborhood are undisturbed. All those 

 effects are subject to infinite variation, according to the conducting powers of 

 the bodies, and of the parts of the earth to which they are attached. 



If the great lightness of the clouds prevents them from falling sufficiently low 

 to be in electrical communication with the ground, then the electricity will be 

 discharged at a distance, attended by the flash of lightning and the roll of thun- 

 der. The electric tension will gradually diminish, rain will ensue, and the 

 cloud will rise. 



The sound which sometimes accompanies this phenomenon is attributed, 

 by M. Peltier, to a number of small partial explosions, which take place be- 

 tween the cloud and ground. They are louder in the case of water-spouts 

 which traverse the land, because of the imperfectness of the conductors pre- 

 sented to them ; they lose their intensity over the sea because water is a bet- 

 ter conductor. 



Considering the progress of the air under the different attractions and repul- 

 sions to which it is submitted, and the contrary and unequal currents encounter- 

 ing different obstacles, M. Peltier endeavors to explain how the direct motion 

 impressed on the air is changed into a gyratory motion more or less decided. 

 It results from this, that the same meteor may present at different moments an 

 example of direct and gyratory motion. 



When the meteor is presented over water, its inductive action gives to the 

 water near the surface an opposite electricity, and a consequent attraction en- 

 sues. If the contrary fluids do not unite by explosion, the surface of the water 

 will swell upward at the several points of attraction, and the moment a dis- 

 charge takes place, and the contrary fluids unite by explosion, this elevation 

 subsides. 



If, however, the electrified cloud is formed with points or prominences, 

 which favor the escape of the electric fluid, the water becomes charged with 

 the fluid descending from the cloud, and, being similarly electrified, is repelled ) 

 by the cloud, and therefore depressed. Currents result from this in the water, ' 

 which soon acquire a vortical motion. 



On similar principles, M. Peltier explains the rapid disappearance of pools, , 

 or small collections of water, the entire mass being electrified by induction, 

 and raised like trees and other objects. 



The discharge of electricity through water may kill the fish contained in 

 it ; but the mere transmission of an electric current through the liquid without 

 explosion will not have this effect, unless a considerable elevation of tempera- > 

 ture takes place. An electric discharge passing near water, but not through < 

 it, may kill animals in it, by the effect of the lateral shock. By these pnnci- > 

 pies, many of the observed effects of water-spouts are explained. 



When by induction the electrical tension of the ground and objects upon it 

 is elevated, the fluid with which it becomes charged will have a tendency to 

 escape by all pointed conductors, and to issue upward toward the cloud. 

 the conductor be imperfect, an elevation of temperature will attend these up- 

 ward currents, the effects of which will be apparent in the conductors by which 



