I2 4 



SEVENTEENTH CENTURY. 



TT. III. 



same kind of electricity repel each other. If you hang a 

 piece of paper, or better still, a pith ball a, upon a silk 

 thread , and hold near to it a piece of sealing-wax c rubbed 

 with dry flannel, you will find that the ball will at first be 

 attracted towards the sealing-wax as in i, Fig. 17, but after a 

 few moments it will be repelled and will draw back as in 2 ; 

 nor will it approach the sealing-wax again till it has been near 

 some other body, and given up part of the electricity it has 

 received. Thus an electrical body, as Guericke pointed out, 



Pith-ball, attracted and repelled by rubbed sealing-wax. 



attracts one that is not electrified, but repels it again as soon 

 as it has filled it with electricity like itself. He was also the 

 first to notice the spark of fire and crackling sound which 

 are produced by electricity when it passes between two 

 bodies which do not touch each other. 



Foundation of the Royal Society of London and other 

 Academies of Science, 1645. We must now return to Eng- 

 land, where about this time an event took place which, 

 though it seemed insignificant at the time, had in the end a 

 great influence upon science. In the year 1642 the unfor- 

 tunate King Charles I. began that civil war with his people 

 which ended in his being beheaded on January 30, 1649. 

 During these years all England was in a state of turmoil and 

 confusion, and in London especiall) the riots and disturb- 



