■s.\> 



- OF Till: AMERK AN ACADEMY. 



irun cylinder of tn = 300, as being unwarranted. He determines N by 

 both the ballistic and magnetometric methods for a rod of m = 300 



by baok-shearing the ballistic curve into the normal curve, using 

 .V j = 0.0005, according to Du Bois, thus finding the N to be 0.0028 

 for the magnetometric method. He would, therefore, correct Mann's 



FlOURB 19. 



Back-shearing curves for Ewing's soft iron wire of diameter 168 cm. Deter- 



mined from results found in the present paper. 



values of JV by adding <>.<>< i-jo to each X throughout. Now it seems 

 to us quite clear, as remarked somewhere in the earlier part of this 

 paper, that we have no right to assume that the normal / vs. // curve, 

 as obtained hallistically, should be even approximately the same as the 

 Mean / vs. Mean // curve of the magnetometric method. This as- 

 suniption is rendered particularly doubtful when we see the very wide 



