16 



Mr. Carl Barus on the 



and K the resistance of the uncompressed glass shell. SR/R 

 is the increment of resistance, R, corresponding to the pressure- 

 increment Sp, where the initial pressure is at least 50 atmo- 

 spheres (§ 7). k r =8U/R,.8p is the pressure-coefficient. To 

 save space, I have taken the mean of the two or three complete 

 triplet observations for each Sp given. The Table contains 

 six independent series of experiments, made at different times 

 and often with different tubes. The adjustment, however, was 

 in the main that of fig. 2, reversed. 



Table I. — Apparent Effect of Pressure (in atmospheres) on 

 the Resistance of Glass, in an insulating medium of 

 Animal Sperm-Oil. 



Series No. 









1 



Series No. 









9. 

 E. 



io 3 x 



3E/E. 



Sp. 



10 6 X£r. 



9. 

 E. 



10 3 X 

 <5E/E. 



dp. 



10° x£,-. 



Mean £>xl0 6 . 



i 









Mean Jc r X 10 6 . 









I. 



82 



470 



174 



III. 



51 



480 



110 



215°. 



160 



835 



193 



310°. 



99 



877 



113 



117xl0 3 u,. 



213 



1180 



181 



— 



165 



1320 



125 



182. 









116. 







1 

 I 



I. 



75 



455 



167 



IV. 



164 



450 



365 



215°. 



157 



825 



191 



100°. 



330 



930 



355 



117xl0 3 w. 



217 



1160 



188 











182. 









360. 









I. 



59 



497 



119 



IV. 



112 



515 



217 



310°. 



117 



830 



142 



160°. 



102 



525 



196 



6xl0 3 o>. 



170 



1175 



145 





111 



610 



185 



137. 









200. 









I. 



61 



470 



130 











310°. 



116 



845 



136 



VI. 



420 



605 



685 



6xl0 3 w. 



158 



1155 



137 



100°. 



420 



650 



640 



134. 









— 

















660. 









II. 



67 



390 



171 



VI. 



127 



655 



194 



215°. 



135 



750 



180 



160°. 



136 



644 



211 



122xl0 3 w. 



195 



1070 



182 





141 



674 



209 



178. 









203. 









II. 



49 



450 



112 



VI. 



126 



657 



192 



310°. 



97 



790 



122 



215°. 



123 



691 



177 



9xl0 3 w. 



145 



1120 



127 





127 | 



688 



184 



121. 









184. 









III. 



85 



516 



163 



VI. 



97 



689 



143 



215°. 



165 



1000 



163 



310°. 



89 



639 



138 



130 x10V 



219 



1405 



156 



]0 4 (U. 









161. 









140. 









