Measures with various dielectrics 267 



when the breadth of the sliding plate was required to be 37 in order that it 

 should sep. pos. 



After the plate was cold it was tried again, the breadth of the sliding plate 

 was obliged to be 36. 



Hence it would seem as if the charge both of glass and of rosin plate was 

 the same when hot as when cold, the small difference between them being most 

 likely owing to the electricity spreading more on the surface of the warm plate 

 than of the cold one. 



550] Crown with slit coat-ings and H with oblong compared with white cylinder; 

 also second thermometer tube with D + E + F. 



The slit coatings were taken from H and plain coatings, 6-03 square, put in 

 their room. 



Sun. March 7 [1773]. Th. 56. N. 15. 



Straw elect, at 2 + 3, which is equivalent to light paper electrometer [4 obs.]. 

 Elect, at 3 + i [6 obs.]. Elect, at i + 3 [7 obs. Art. 660]. 



Mon. Mar 8 [1773]. Th. 54. N. 14^. [4 obs.]. 



551] Quantity of electricity in plate D and rosin with brass coatings compared 

 with that of tin circle of 36" and one of 30" by machine for trying simple plates*; 

 with different degrees of electrification]. 



Tu. Mar. 9 [1773]. Th. 51. N. 15. 



The exper. of p. 78 [Art. 547] repeated, only using square tin plates of different 

 sizes made to fasten on to sliding cylinder instead of the sliding trial plates. 

 The tin circles and the square plates both supported on silk. 

 Straw el. at inner marks N 2. 



* [Art. 240.] f [Art. 664.] 



