﻿452 Prof. Lyle and Mr. Baldwin on Propagation of 



It will be noticed (see Table XII.) that in this specimen 

 also the positions of max. retardation and max. leakage 

 coefficient very nearly if not qnite coincide. 



10. The cause of the difference in the leakage-curves for 

 the two rods is naturally to be looked for in their very different 

 permeability-curves. Of the flux F which crosses any section 



Fig-. 7. 



120 cms. 



of the rod, — dF leaks out in the next elementary length dx,, 

 and F + dF continues in the rod, and the ratio of — dF to 

 F+dF {i.e. —dFIF in the limit) will, when the magnetizing 

 force is constant, be equal to the inverse ratio of the reluct- 

 ances of the two corresponding paths. When the magnetizing 

 force is periodic, the phenomenon is further complicated by 

 the eddy currents set up in the rod, giving rise to back 

 magnetomotive forces. If, for two different rods, the reluct- 

 ances of two elementary leakage-paths (air) were equal, then 



