260 



^Journal of Experiments, Feb. 1773 



The same repeated with neg. elect. 



536] H with slits and a crown glass with oblong coating compared with white 

 cylinder; also A and C with slits compared with B. 



The coatings were taken off from the plates A, C and H, and oblong coatings 

 with slits put in their room; an oblong coating without slits was also put to 

 a piece of crown glass, vide Measures [Art. 593]. 



Tu. Feb. 9 [1773]. Th. 50. N. 12^. 50 observations. [Art. 660.] 

 These plates were tried with middle cork balls. 



Spreading of el. on surf. 

 A & C. Balls at first sep. wider. Closed in about 10". 



B. D, but rather sooner. As it was supposed that this proceeded from 

 the wires not conducting ready enough, the machine was moved slower, there 

 was then but little of this and B was a great while before it closed, C about 

 5", H a great while. 



It was suspected that this increase of separation of the balls before they 

 closed was owing to the wire designed to carry off el. to earth f not conducting 

 fast enough. To try this, the next evening a long wire was insulated, and the 

 cork balls hung to it. It was electrified sufficiently to make them sep. about 

 an inch. They closed instantly on touching the wire with a bit of iron either 

 communicating with wire for carrying off el. to ground, or whether it was only 

 held in the hand. The air was as dry as the night before. 



* [Divisions and quarter divisions.] 



f [Art. 258.] 



