BABBITT. — THE VON WALTENHOFEN PHENOMENON. 263 



The three curves, Figures 19, 20 and 21, show the results of the 

 investigation. 



Evidently the 24-, 22- and 28-step reversals fall very nearly on the 

 corresponding 1-step curves and are for all practical purposes equal in 

 their flux change to the 1-step reversals. 



Some of the peculiarities that appeared in the early curves of toroids 

 I and II do not appear in these curves so prominently. However, III 

 has been magnetized a large number of times in previous investigations 

 and could not be expected to yield other than the results actually 

 obtained. 



Summary. 



The uniformity of the results for all three toroids leads to the con- 

 clusion that, in the early stages of its magnetic history, the condition 

 of the iron is constantly changing. During this stage of transition no 

 given condition can be repeated by any of the ordinary methods of 

 demagnetization and remagnetization ; but as the mass is subjected 

 again and again to the magnetizing process it attains more and more 

 nearly to a condition such that, for all practical purposes, any mag- 

 netic state may be repeated as often as desired. 



The process of demagnetization affects, by the manner in which it is 

 carried out, the first few hysteresis curves that follow. This effect, in 

 so far as the present investigation determined its extent, consists in a 

 change in the maximum induction attained when the maximum field 

 for the particular curve in question is applied. 



The various stages through which the iron passes during its early 

 magnetic history are the more numerous for the low flux densities and 

 disappear almost completely as the point of saturation is approached. 

 It is possible that, if one started with a high flux density and came 

 down to the lower, another set of phenomena might appear. 



The work on the large solid magnet showed conclusively that the 

 form of the hysteresis curve depended upon the number of steps 

 employed. The corresponding experimentation on finely divided 

 masses, both large and small, indicated that the hysteresis cycle was 

 not affected by the number of steps. Such was found to be the case 

 in three distinct specimens of iron ; for wherever the curves could be 

 exactly determined, the points derived from the two methods of pro- 

 cedure, one by a small number, and the other by a large number of 

 steps, fell, within 0. 1 of one per cent, on a smooth curve. An obvious 

 reconciliation of the two results lies in regarding the eddy currents, and 

 not any inherent property of the iron, as responsible for the observed 



