342 



Scientific Proceedings, Royal Dublin Society. 



A similar test was made on a sheet of white erinoid, but there was no 

 variation of D for a voltage of 590 applied for over three minutes in each 

 direction. In each case the value of D was 110 divisions. 



Thus while fibre showed the presence of dielectric absorption the sample 

 of erinoid did not. This was generally found to be the case for the latter 

 material. 



The results given in Tables 3 and 4 are for tubes of erinoid which have 

 been machined. A set of tests was made on samples in the form of sheets 

 whose surfaces had not been machined or prepared in any way. The results 

 are given in Table 6. 



Table 6. 



These results, excluding those of the fourth section, are plotted in Fig. 2. 



