M. M. Block^*, E. B. Brucker, I. S. Hughes^†, T. Kikuchi, and C. Meltzer

• Duke University, Durham, North Carolina

F. Anderson^‡ and A. Pevsner

• The Johns Hopkins University, Baltimore, Maryland

E. M. Harth and J. Leitner

• Syracuse University, Syracuse, New York

H. O. Cohn

• Oak Ridge National Laboratory, Oak Ridge, Tennessee

• ^*John Simon Guggenheim Memorial Fellow 1958-59, on leave of absence at University of Bologna, Italy.
• ^†Now at Department of Natural Philosophy, The University, Glasgow, Scotland.
• ^‡On leave of absence from University College, Dublin, Ireland.