CHAPTER XXXVII 



THE EXPERIMENT WITH PAPER 



SINCE the cat threatens to get cross, we will 

 have recourse to another way of producing 

 electricity. 



"You fold lengthwise a good sheet of ordinary 

 paper ; then take hold of the double strip by each end. 

 Xcxt, you heat it just to the scorching point over a 

 stove or in front of a hot fire. The greater the heat, 

 the more electricity will be developed. Finally, still 

 holding the strip by the ends alone, you rub it 

 quickly, as soon as it is hot, on a piece of woolen cloth 

 previously warmed and stretched over the knee. It 

 can be rubbed on the trousers if they are woolen. 

 The friction must be rapid and lengthwise of the 

 paper. After a short rubbing the band is quickly 

 raised with one hand, with great care not to let the 

 paper touch against anything ; if it did the electricity 

 would be dissipated. Then without delay you bring 

 up the knuckles of your free hand, or, better, the end 

 of a key, near to the middle of the strip of paper ; 

 and you will see a bright spark dart from the paper 

 to the key with a slight crackling. To get another 

 spark you must go through the same operations 

 again, for at the approach of the finder or key the 

 sheet of paper loses all its electricity. 



"Instead of making a spark, you can hold tin- elec 



163 



