Research in solid state physics from period of Sommerfeld's institutes; thesis, work in Frankfurt and Stuttgart; writing of Sommerfeld-Bethe Handbuch article. Also prominently metioned are: Patrick Maynard, Stuart Blackett, Felix Bloch, Clinton Joseph Davisson, Lester Halbert Germer, Werner Heisenberg, Irwin Madelung, Herman Francis mark, Sir Rudolf Ernst Peierls, Robert Wichard Pohl, Erwin Schrödinger, and Arnold Sommerfeld.