476 THE INTELLECTUAL RISE IN ELECTRICITY. 



outgrow the gallery. Then he erected the first aerial line 

 of communication on poles, extending over his land for a 

 distance of 650 feet. The weather was warm it was July 

 and the experimenters were ablaze with enthusiasm. In 

 fact, they exerted themselves so much in running from 

 one end of the line to the other, Wheler now rubbing the 

 tube and Gray watching the bits of foil, and then vice 

 versa, that, suddenly, in the late afternoon, when the 

 attraction ceased for the day, Gray naively remarks that it 

 could not positively be said whether this was "caused by 

 the dew falling or by my being very hot, but I rather im- 

 pute it to the latter." 



After discovering that the virtue could be made to travel 

 from the tube over three lines simultaneously, to Mr. 

 Wheler'' s "great parlor, little parlor and hall," Gray de- 

 parts, leaving Wheler to expend his excitement in electri- 

 fying l 'a hot poker, a live chicken, a large map and an 

 umbrella." 



In the fall of 1729 the discovery that the virtue will 

 travel from tube to line and then over the latter without 

 direct contact of the tube or, in other words, by induction 

 is made. Then follow further researches into the elec- 

 trification of different bodies. Gray charges a soap-bubble 

 and makes it attractive. By means of hollow and solid 

 suspended wooden cubes he demonstrates the important 

 fact that the charge is resident on the surface of the elec- 

 trified body, for ''no part but the surface attracts." Then, 

 in the spring of 1730, he suspends a boy, and finds that 

 when the tube is rubbed and held to the boy's feet, the 

 leaf brass is vigorously attracted by the boy's face, thus 

 demonstrating the conductibility of the human body. It 

 is, doubtless, not pleasant to the urchin to feel the fire 

 pattering against his cheeks, but Gray encourages him to 

 bear it manfully, because should he turn the back of his 

 head the virtue, says the discoverer, would be greatly "cut 

 off by the short hair." 



In the fall of 1730 Wheler again appears with his un- 



