On the Explosive Effect of Electrical Discharges. 

 Cyclical Magnetization Curves [continued). 



279 



Loop V. 



H. 



B. 



H. 



B. 



H. 



B. 



H. 



B. 



7150 



8930 



631 



5760 



-10-52 



-4189 



-43-47 



-7996 



4386 



8262 







4290 



-2410 



-6628 



-49 00 



-8116 



3207 



7715 



-2-20 



2937 



-31-75 



-7289 



-51-11 



-8239 



1055 



6311 



-7 04 



-2473 



-36-58 



-7640 



-71-50 



-8930 



Loop. 



B (max.). 



Hysteresis Loss. 



Ergs per cc. 

 per cycle. 



Watts per lb. 



per 100 cycles 



per sec. 



I 



II 



1475 

 2545 



3865 

 5972 

 8930 



466 



1288 



2997 



7397 



13423 



•300 



•829 



1-934 



4-765 



8-658 



Ill 



IV 



V 



The result of experiments with the cast cobalt ring is to 

 show that although in general form its magnetization-curve 

 resembles that of cast iron, its hysteretic exponent is similar 

 to that of annealed soft iron. The absolute hysteresis values 

 corresponding to various maximum flux-densities are, how- 

 ever, considerably larger than those of a typical variety of cast 

 iron. 



XXIX. Explosive Effect of Electrical Discharges. 

 By John Trowbridge, T. C. and 1. C. Howe *. 



SINCE the time of Franklin this subject has been studied 

 by numerous investigators ; and a full bibliography of 

 their work is contained in Wiedemann's Galvanismus und 

 Electromagnetismus. 



The resources of the Jefferson Physical Laboratory per- 

 mitting a study of this phenomenon over a greater range than 

 has hitherto been possible, we have undertaken the work in 

 the hope of further elucidating the subject. The Laboratory 

 possesses two high-tension transformers, or Plante rheostatic 

 machines —one giving discharges of 125 centimetres in length, 



* Communicated by the Authors. 



