258 CAUSES OF WHIRLWINDS, ETC. 



electricity is induced into the air along its path, and flows downwards 

 towards the point of emission, or apex of the cone, where the primary 

 charge is most concentrated. Now, it has been proved by experiment, 

 that every electric current contains within itself a revolving action, the 

 consequence of the attraction of the opposite electric surface. To this 

 property of an electric we may therefore assign the origin of the spiral 

 motion of the whirlwind, conceiving that it results from the longitudinal 

 or ascending motion of the stream, influenced by the circular or revolving 

 motion of the two electricities round each other. The velocity of the 

 spiral motion is too great to be followed by the eye, and its mechanical 

 effects, exhibited in the lifting of loaded waggons, the levelling of stone- 

 vails, the cutting through fences, trees, and huts, as if with an edged 

 tool, are ascribable to no other physical cause than electro-dynamic. 



Waterspouts have the same principles of action, but in them the accu- 

 mulation exists in a low heavy cloud, which has induced the opposite 

 electricity into the earth beneath, without finding a prominent point to 

 facilitate an explosion. The charge is gradually neutralised by combina- 

 tion with that rushing in a stream from below, and carrying with it dust 

 from the plain, and vapour, or rather a mist from waters. The watery 

 particles being again aggregated into drops, sometimes as large as 

 cherries, descend in torrents, and a circulation is thus established while 

 the accumulation exists. 



The spouts or tubes, apparently let down from the cloud, are formed 

 by the vapour or mist attracted by the electricity which has elongated 

 itself into a protrusion by an effort to discharge itself. 



FLAKES OF SNOW AS SEEN THROUGH A MICROSCOPE. 



" When icicles hang by the wall, 

 And Dick, the ploughman, blows his nail, 

 And Tom bears logs into the ball. 

 And milk comes frozen home in paiL" 



SHAKSPEARE. 



In this, our climate, we have a very liberal acquaintance with snow, 

 and though to the " unfed sides, and loop'd and window'd raggedness" 

 of many, it is felt as no flattery, yet the value and beauty of its con- 

 struction is as little known to others as if it were only seen in Kamschatka. 

 By the examination of a flake of snow with the assistance of a microscope, 

 we are enabled to judge of its beauty and wonderful structure. 



