264 PROCEEDINGS OF THE AMERICAN ACADEMY. 



variations in the hysteresis curve. In other words, whatever variation 

 exists due to a special property of the iron seems to amount to less 

 than 0.001 of the total flux change. 



In general, therefore, any method of obtaining an hysteresis curve of 

 finely laminated iron will permit one to forecast its future action. It 

 is assumed, of course, that we have carried it past the transitional 

 stage. On the other hand, for solid masses of iron that method should 

 be employed which corresponds as nearly as possible to the future 

 working conditions. 



The Jefferson Laboratory, 

 Cambridge, Mass. 



