194 



PROCEEDINGS OF THE AMERICAN ACADEiD". 



much larger tha/ii the moment of C6, but the value of II corresponding 

 to an induction of 1000 was in each case about 25.9. 



For the rod B4 the relation between H and B is indicated approxi- 

 mately at all events by the numbers given in Table VI. 



Figure 1. 



Table VII gives under //lo,,,, the value of the excitation corre- 

 sponding to B = 1000, and under Bx-iq the value of the induction 

 corresponding to // = 120 for all the rods. 



The specimens used were cast at different times in order that they 

 might fairly represent the best mixtures used by the foundries from 

 which they came, and in view of this fact the near agreement of the 



