On the Causes of the Tornado, or Water Spout. i 55 



those of a Leyden jar or pane ; the air performhig the part of an 

 electric in place of the glass, while the cloud acts as a coating. 



It follows that the phenomena above mentioned as liable to arise 

 between oppositely electrified bodies, may be expected to take place 

 between the clouds and the earth, with effects as much exceeding 

 those produced by human agency, as the snap and spark of an elec- 

 tric battery are exceeded by thunder and lightning. If in the one 

 case pith balls and other light bodies are lifted ; in the other, water, 

 trees, houses, hay-stacks and barns may be powerfully affected.* 

 If from a point electrified by a human contrivance, a blast of air is 

 induced ; it is assuredly not unreasonable to ascribe to the analogous 

 electrical apparatus of nature, aided by the elasticity of the air, a 

 vertical hurricane. It was under the well founded impression that 

 lightning may be superseded by a current, that we have been in- 

 structed by Franklin, to surmount our lightning rods by metallic 

 points, by which electrical discharges from thunder clouds are ex- 

 pected to be conveyed to the earth gradually, which might otherwise 

 pass in sparks of lightning of a formidable magnitude. 



If, then, it be demonstrated that a continuous discharge of electri- 

 city may become the substitute for lightning, and that within the 

 sphere of the discharge the air may be so lifted as to counteract its 



* Thisfigm'e affords an illustration in minia- 

 ture of the rise and fall of bodies situated be- 

 tween oppositely electrified surfaces, which, in 

 the gigantic operations of nature, are conceived 

 to be the exciting cause of the tornado. The 

 phenomena represented by it are designated in 

 Pixii's catalogue as " grele electrique," and may 

 be thus explained. A metallic rod supports one 

 ball within the bell glass, another without, so as 

 to be in contact with the knob of another rod R, 

 proceeding from the conductor of an electrical 

 machine in operation. The brass ball being by 

 these means intensely electrified, attracts some 

 of the pith balls which lie upon the metallic dish 

 in which the bell is situated, and which should 

 communicate with the cushions of the machine. 

 As soon as the pith balls come into contact with 

 the electrified ball, becoming similarly excited, 

 agreeably to the general law they recede from 

 each other and are attracted by the oppositely 

 electrified dish. Reaching the dish, they attain 

 the same electrical state as at first, and are, of 

 course, liable to be attracted again. 



