AN ARTIFICIAL WATERSPOUT. 113 



dangerous to ships that happen to come within their 

 influence. 



That they are caused by electricity has been 

 proved by experiment miniature waterspouts have 

 been produced by artificial means; and as Dr. 

 Bonzano of New York gives particular directions 

 how the thing ought to be done, we quote his words 

 for the benefit of those who happen to possess- elec- 

 trical machines : 



"From the conductor of an electrical machine 

 suspend, by a wire or chain, a small metallic ball 

 (one of wood covered with tinfoil) ; and under the 

 ball place a rather wide metallic basin, containing 

 some oil of turpentine, at the distance of about 

 three-quarters of an inch. If the handle of the 

 machine be now turned slowly, the liquid in the 

 basin will begin to move in different directions and 

 form whirlpools. As the electricity on the con- 

 ductor accumulates, the troubled liquid will elevate 

 itself in the centre, and at last become attached to 

 the ball. Draw off the electricity from the con- 

 ductor, to let the liquid resume its position ; a por- 

 tion of the turpentine remains attached to the ball. 

 Turn the handle again very slowly, and observe 

 now the few drops adhering to the ball assume a 

 conical shape, with the apex downward ; while the 

 liquid under it assumes also a conical shape, the 

 apex upward, until both meet. As the liquid does 

 not accumulate on the ball, there must necessarily 

 be as great a current downward as upward, giving 



(451) 8 



