Peirce— Permeabilities and Reluctivities for Steel. 279 

 Fig. '6. 



j4l -* 1 



The moment of inertia of the suspended coil of the long 

 period ballistic galvanometer used for the work was so great 

 tha at Tow excitations the instrument was rather insensitive 

 when used to measure the difference of the fluxes through 



