of Glass at different Temperatures, 231 



Experiment IV. 

 Temperature. Resistance. Temperature. Resistance. 



74 37xl0 10 | 83 14xlO u 



98 43xl0 9 98 45 x 10 10 



127 57xl0 8 128 60xl0 9 



147 163 xlO 7 147 19 x 10 9 



166-5 48xl0 7 166-5 53xl0 8 



185-5 18xl0 7 184 204 xlO 7 



201 9Sxl0 6 204 57xl0 7 



220 51xl0 6 ? , 214 46xl0 7 



225 51xl0 6 224 27 x 10 7 



246 27xl0 6 230-5 19 x 10 7 



*247 ...... 57xl0 6 247 57 x 10 6 



The battery was reversed at the end of this experiment] and 

 the following; resistances were then obtained : — 



80 31xl0 10 



77 57xl0 10 



74 85xl0 10 



71 115xl0 10 



68 160xl0 10 



The following table of results, extracted from an unfinished 



series of experiments on the resistance and specific inductive 



capacity of porcelain, may be interesting : — 



Resistance, in ohms, Temperature 



per cubic centimetre. lempeiatuie. 



12xl0 12 68 



86xl0 n 73 



27xlO u 86 



68xl0 10 103 



12xl0 10 130 



30x10° 150 



94xl0 8 170 



35xl0 8 185 



20xl0 8 200 



60xl0 7 220 



23xl0 7 250 



97xl0 6 270 



44xl0 6 290 



73xl0 6 270 



56xl0 7 220 



19xl0 8 200 



41xl0 8 185 



92xl0 8 170 



47xl0 9 144 



15xl0 10 125 



74xl0 10 100 



* The temperature was kept about 247° for half an hour before the 

 reading for resistance was taken, 



