VOL. XL!.] PHILOSOPHICAL TRANSACTIONS. 315 



the same length, suspended from a silk line, vibrated backward and forward 2 

 or 3 times, being first attracted, and then repelled, and continuing some time 

 repelled; but on joining the top of the tube, by a packthread going round it, 

 to the loop of the thread, the thread continued constantly in a state of repul- 

 sion, showing no tendency to attraction. 



Exper. g. — Two black silks, about the same length with the thread in the 

 preceding experiment, were suspended by loops from a horizontal red silk line, 

 at the distance of about half an inch from each other ; on holding the excited 

 tube under them, the silks swelled out from one another, and then jumped 

 away on each hand to the distance of 1 feet. 



Exper. 10. — A circular board of nearly the same diameter with the electric 

 cake, was suspended horizontally by 6 silk lines, tied to one silk line which was 

 brought over a pulley at the top of a frame of wood, so as to be moved up and 

 down. From the board hung 6 fine white threads, about 18 inches long, fixed 

 by a little cement at equal distances from each other. The board being let 

 down till the ends of the threads were about an inch distant from the electric 

 cake, which was directly under, and had the ivory ball on its centre ; the 

 threads all approached towards the centre of the cake, both when the ball was 

 in the centre, and when taken away, keeping an equal distance from the centre, 

 and from one another, as long as a packthread joined the circle of board and the 

 frame to keep it steady ; and on removing the ball out of the centre, towards 

 the circumference, the figure lengthened, the threads next the ball advancing 

 nearer the circumference ; when the ball was placed at about an inch distance 

 from the circumference, the thread that was before nearest the circumference 

 whipped between the ball and the centre, so as to be almost in the same plane 

 with its two neighbouring threads, the figure formed by the extremities re- 

 sembling an ellipse with one end cut off. But when, instead of the packthread 

 that joined the board to the frame, a blue silk line was tied in the same manner 

 in all respects, the threads, instead of coming towards the centre, all flew away 

 at a great distance from the cake, and from one another. 



It ought to be observed in the experiments of the circular motion of the pen- 

 dulous body, that Mr. Wheler's hand seemed as steady as possible, except in 

 the first experiment, when a little trembling appeared; Mr. George Graham 

 taking a very good method to observe it, by keeping his eye fixed on a point at 

 a considerable distance, in the same line with the end of Mr. Wheler's finger 

 and his own eye. 



Yet when Mr. Wheler had finished the experiments to the satisfaction of all 

 present, Mr. Hawskbee, Mr. George Graham, and Dr. Mortimer, held the 

 thread with the pendulous body over the cake with the ball on its centre, after 



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