526 The Kev. T. E. Robinson's Experimental Researches on the 



Table XXXIV. 



For the same -f , L is less than even in Table xxxii., the inferior inductive 

 transmission of the keeper and base lowering the excitation of the cylinders. 

 The fifth column shows that the average change of L for a given change of ^ 

 is less, but that it is more uniform, being in fact almost constant within the 

 range of the positive values. It is probable that for the three magnets, the 

 maximum L is about 300; now with the iron one -f = 2592 gives ^ of this; 

 with the compound 2960 gives f of it, and with the steel 2961 gives -f^. With 

 a reversed current L continues positive much longer than in the preceding 

 case, as might be expected from the permanent magnetism of the keeper and 



