CHAPTER XXIX 

 STATIC ELECTRICITY 



163. Electricity by Friction. If a fountain pen, comb, or 

 other object made of rubber, or an ebonite rod, be rubbed 

 rapidly with a piece of woolen cloth such as a coat sleeve, the 

 object will attract small bits of paper, shavings, and the like, 

 exactly as a magnet picks up bits of iron and steel. A similar 

 effect may be seen when a sheet of paper is warmed and rubbed 



FIG. 70. The Toeppler-Holtz induction machine. (Tower, Smith 

 and Turton.) 



vigorously with the hand or a woolen cloth. It will then 

 attract other bits of paper, or cling to the wall or door if pressed 

 against it. Sometimes the rubbing in this way may even 

 produce a spark, as when one combs the hair with a rubber 

 comb, or strokes a cat on a cold dry day. By scuffling about 

 on a thick carpet, one may sometimes produce a spark large 

 enough to light the gas when it is touched by the finger. 



199 



