Valasek, J.2016-03-092016-03-091922-05https://hdl.handle.net/11299/178093University of Minnesota Ph.D. dissertation. May 1922. Major: Physics. Advisor: Professor W. F. G. Swann. 1 computer file (PDF); 13 pages. [479-491]. Reprinted in Physical Review.enPhysicsThesis or Dissertation