Specific inductive capacity 247 



The trial plate 4 is on same plate as 5, and the area of one division on it is 

 to that of 5 on trial plate 5 as r8 2 to 9. 



508] Thick white, 2 nd rosin, D and F of Nairne, and the two double plates 

 together, compared together, also thin white with D and E and D and F. 



Sat. Dec. 5 [1772] in evening. Th. 56. N. 28^. 



[24 observations.] 



N.B. Before these exper. were tried, the plates E and F were freed from 

 cemfent] and coated afresh with plates of same size. The plate D was also 

 freed from the varnish and coated afresh, and the trial plate B was freed from 

 cement and coated with rather larger plates. 



Hence it should seem that thick ros. contained n inc. el. less than the 

 doub. plates A or B, id est 18-2 inc. el., that the thick white contained same 

 as D, id est 36 inc., and that 2 nd ros. contained 2-03 inc. less, id est 34 inc., which 

 differs very little from p. 12 [Art. 501]. 



509] Whitish plate, P, Q, O, old G and thin rosin compared with M. 



Sun. Dec. 6 [1772]. Th. 54. N. 20. 



[19 observations, Art. 655.] 



[Result.] By these exper. the two double plates should contain about 

 1-13 inc. el. more than D, that thick white contained same as D, that the 2 nd 

 rosin contained 2-26 less, that the thin white contained -45 less than D + E, 

 and that N contained 1-81 less. 



Sunday evening. Th. 57^. N. 17^. 

 [18 observations.] 



510] Crown A and C compared with A, B and C of Nairne. 



Mon. Dec. 7 [1772]. Th. 55. N. i8J. 



[10 observations. 



21 observations of spreading of electricity on the different plates.j 



By the above exper. Crown A and C should contain 15 inc. el. less than A. 



511] Whether the shock from the plate air was diminished by changing the air 

 between them by moving them horizontally*. 



Sat. Dec. 18 [1773 f]. Th. 60. N. 23^. 



It was tried whether shock in charging plate air was sensibly diminished by 

 moving the 2 plates horizontally, and thereby changing the air between them 

 in the manner represented in figure, where AB represents the two 8-inch brass 

 plates with sealing wax between them suspended by the silk strings AC and BD. 



AE and BF are silk strings fastened to the frame on which lower plate 

 rests, and passing over wire hooks E and F, and stretched by weights so that 

 the plates would move from E towards F and rest in any position. 



The electrifying wire was suspended by the string G with a counterpoise. 



* [See Arts. 345, 516.] f [Probably Dec. 19, 1772. See Art. 502.] 



