302 



Scientific Proceedings, Royal Dublin Society. 



Table 6. 



Sample C. 



Thickness 065 cms. 



From Figs. 4, 5, and 6 it is at once seen that this old type of insulator 

 was made of different material from that of the recent low tension insulators 

 A and B. Its material possessed a higher insulation resistance. The line 

 or C is not drawn in Fig. 6, but it falls nearest to that drawn for F. 



Table 7. 



Sample D. 



Thickness 022 cms. 



