M. Tinkham and M.W.P. Strandberg."February 1, 1955"--Cover. "Reprinted from The Physical review, vol. 97, no. 4, 937-966, February 15, 1955."Includes bibliographical references.Army Signal Corps Contract DA36-039 sc-42607 Project 132B Dept. of the Army Project 3-99-12-022