PROGRESS IN ELECTRICITY 



electrical fire." In his description of this phenomenon, 

 Franklin writes : 



" Place an iron shot of three or four inches diameter 

 on the mouth of a clean, dry, glass bottle. By a fine 

 silken thread from the ceiling right over the mouth of 

 the bottle, suspend a small cork ball, about the big- 

 ness of a marble; the thread of such a length that 

 the cork ball may rest against the side of the shot. 

 Electrify the shot, and the ball will be repelled to the 

 distance of four or five inches, more or less, according 

 to the quantity of electricity. When in this state, if 

 you present to the shot the point of a long, slender 

 shaft-bodkin, at six or eight inches distance, the re- 

 pellency is instantly destroyed, and the cork flies to 

 the shot. A blunt body must be brought within an 

 inch, and draw a spark, to produce the same effect. 



" To prove that the electrical fire is drawn off by the 

 point, if you take the blade of the bodkin out of the 

 wooden handle and fix it in a stick of sealing-wax, and 

 then present it at the distance aforesaid, or if you bring 

 it very near, no such effect follows; but sliding one 

 finger along the wax till you touch the blade, and the 

 ball flies to the shot immediately. If you present the 

 point in the dark you will see, sometimes at a foot dis- 

 tance, and more, a light gather upon it like that of a 

 fire-fly or glow-worm; the less sharp the point, the 

 nearer you must bring it to observe the light; and at 

 whatever distance you see the light, you may draw off 

 the electrical fire and destroy the repellency. If a 

 cork ball so suspended be repelled by the tube, and a 

 point be presented quick to it, though at a considerable 



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