254 EIGHTEENTH CENTURY. pt. Ill 



newest improvements in printing. After a time he went 

 back to Philadelphia, and from that time he began to succeed 

 as a printer and became a well-known and respected man. 



It was in the year 1746 that he first began to pay atten- 

 tion to the experiments in electricity which were being made 

 in England and France. A great deal had been learnt 

 about this science since the time when Otto Guericke made 

 the first electrical machine in 1600, and a Frenchman named 

 Du Faye had shown that two different kinds of electricity 

 could be produced by rubbing different substances. You will 

 remember that a pith-ball, when filled with electricity from 

 a stick of electrified sealing-wax, draws back, and will not 

 approach the sealing-wax again (seep. 124). But Du Faye 

 discovered that if you rub the end of a glass rod with silk, 

 and bring it near to this ball, it will draw the ball towards 

 itself, showing that the electricity in the glass rod has 

 exactly the opposite effect to that in the sealing-wax. In 

 other words, while Guericke had shown that substances 

 filled with the same kind of electricity repel each other, Du 

 Faye showed that substances filled with different kinds of 

 electricity attract each other. Both these men thought that 

 electricity was a fluid which was created by the rubbing, and 

 which was not in bodies at other times ; when Franklin, how- 

 ever, began to make his experiments he saw clearly that this 

 was not as they had supposed, but that all bodies have more 

 or less electricity in them, which the rubbing only brings out. 



The way in which he proved this is very interesting ; 

 but to understand it you must first know that any body 

 which is to be filled with electricity requires to be so placed 

 that the electricity cannot pass away from it into the earth. 

 The best way to do this is to stand it upon a stool with glass 

 legs, because electricity does not pass easily along glass. 



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