VOL. XXXVII.J PHILOSOPHICAL TRANSACTIONS. 569 



of them on cakes of rosin, and suspending the other on the hair-lines; arid the 

 effect was the same as above related. He then caused both the boys to stand 

 on cakes of rosin, giving them to hold a part of a Spanish cane fishing-rod, of 

 8 feet long, one boy holding one, and the other boy the other end of the rod; 

 then the leaf-brass being laid on the stand, and one of the boys holding his 

 hand over it; Mr. Gray went to the other boy, and the excited tube being held 

 near the palm of his hand, the first boy's hand attracted and repelled the leaf- 

 brass strongly. A piece of packthread was then given them to hold by each 

 end, about the same length with the rod, viz. 8 feet long. Under each of their 

 hands was laid leaf-brass ; then going to the middle of the line, holding the 

 tube near it, the farther hand of both the boys attracted the leaf-brass with so 

 much vigour, that it is not to be doubted that had the line been much longer, 

 they would have attracted at a far greater distance. He then caused the boys 

 to stand on the cakes of rosin, so as to let the flaps of their coats touch, and 

 then by holding the tube to one of their hands, the other hand attracted, but 

 not with more force than when they were distant the length of the line. They 

 then stood so much farther as not to let their coats touch by about an inch, and 

 then exciting one of them to attract, the other received not the least degree of 

 attraction. He then bid one boy put his finger upon the other boy's wrist, and 

 then he immediately became electrical. 



Oct. 4, Mr. Gray made the following experiment: a fishing rod of about 10 

 feet 8 inches long, being horizontal, and over it, towards the less end, a small 

 rod, being the top end of another fishing-rod, at the less end, which was 

 whalebone, there was put on a ball of cork 2 inches diameter, the small rod 

 touching the great one ; then the tube being excited, and held near the large 

 end of the great rod, applying it as usual ; on going to the cork with a pendu- 

 lous thread, he found it attracted it at the distance of at least 2 inches. Then 

 the rod was moved higher, so as not to touch the end of the long rod, by 

 estimation about an inch, and after several trials, there was a visible attrac- 

 tion, when the little rod that carried the ball was above the great one 34 

 inches. 



Oct. 5, he took a line of packthread 17 feet 4 inches long, with silk lines 

 tied to the ends of the packthread, one of them about 4, the other 2 feet long, 

 near two of the opposite corners of his chamber, where in each of them wag 

 driven a hook at about 3-1 feet high, to which the ends of the silk were fastened, 

 drawn so tight as to bear the packthread nearly horizontal : then the small par 

 of the fishing-rod was suspended over the packthread at about 4 feet from the 

 end ; then the tube being applied to the other end of the packthread, the cork 



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