WATERSPOUTS AND WHIHLWINDS. 



673 



" The column had extended to about two thirds of the way toward the sea, 

 and nearly connected itself with the basin, when a heavy shower of rain feli 

 from the right of the arch, and shortly after another fell from the opposite 

 side. This discharge appeared to have an effect on the water-spout, which 

 now began to retire. 



" The sea, on the contrary, was perceptibly more agitated, and for several 'i 

 minutes the basin continued to increase in size, although the column wan con- < 

 siderably diminished (fig. 5). 



Fig. 5. 



" In a few minutes more the column had entirely disappeared. The sea. 

 however, still continued agitated, and did not subside for three minutes after all 

 the disturbing causes from above had vanished. The phenomenon was unac- 

 companied by thunder or lightning, although the showers of rain which fell so 

 suddenly seemed to be occasioned by some such disturbance." 



M. Peltier has attempted to illustrate the electrical origin of these phenom- 

 ena by producing them artificially. With this view he has represented the 

 cloud in which the meteor originates by a globe of metal kept constantly charg- 

 ed with electricity by a machine. The inequalities of the cloud he represent- 

 ed bv points raised on the surface of a globe. By means of the influence 

 which this globe exercised upon water, vapors, and dust, he was able to pro- 

 duce a depression of the liquid, and the vortical or gyratory motion, and some 

 other effects similar to those observed in the meteor. 



All these effects disappeared when the globe was divested of points. In 

 this case, instead of a depression, an elevation was produced ; the vapors 

 rose under the smooth ball, but showed little agitation. When the points 

 were restored, the vapor was increased in more than a threefold proportion. 



The globules of vapor, being electrified at a distance by the pointSj were 

 repelled in all directions, and made to whirl, more or less, according to the de- 

 gree of the electric charge. 



There are other electrical experiments made with other views, which M. 

 Peltier brings to bear on the illustration of water-spouts. 



A plate of copper, not insulated, being placed under a sphere, a little light 

 ball is placed between them. When the sphere is electrified, the ball plays 

 alternately upward and downward between the sphere and the plate ; but if, 

 instead of the ball, elongated or flat bodies be interposed, so as to present only 

 a long and narrow strip of gold leaf, the alternate motion just described is 

 transformed into a vortical motion, which ultimately becomes one of rapid ro- 



