A HISTORY OF SCIENCE 



to place it in close proximity to the other whirling 

 cylinder. 



These demonstrations of Hauksbee attracted wide 

 attention and gave an impetus to investigators in the 

 field of electricity ; but still no great advance was made 

 for something like a quarter of a century. Possibly 

 the energies of the scientists were exhausted for the 

 moment in exploring the new fields thrown open to 

 investigation by the colossal work of Newton. 



THE EXPERIMENTS OF STEPHEN GRAY 



In 1729 Stephen Gray (died in 1736), an eccentric 

 and irascible old pensioner of the Charter House in 

 London, undertook some investigations along lines 

 similar to those of Hauksbee. While experimenting 

 with a glass tube for producing electricity, as Hauksbee 

 had done, he noticed that the corks with which he had 

 stopped the ends of the tube to exclude the dust, 

 seemed to attract bits of paper and leaf -brass as well 

 as the glass itself. He surmised at once that this mys- 

 terious electricity, or "virtue," as it was called, might 

 be transmitted through other substances as it seemed 

 to be through glass. 



" Having by me an ivory ball of about one and three- 

 tenths of an inch in diameter," he writes, " with a hole 

 through it, this I fixed upon a fir-stick about four inches 

 long, thrusting the other end into the cork, and upon 

 rubbing the tube found that the ball attracted and 

 repelled the feather with more vigor than the cork had 

 done, repeating its attractions and repulsions for many 

 times together. I then fixed the ball on longer sticks, 

 first upon one of eight inches, and afterwards upon one 



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