In the second edition, some new topics were added, including the Stokes parameters, the Kramers–Kronig dispersion relations, and the Sommerfeld–Brillouin problem. The two chapters on special relativity were rewritten entirely, with the basic results of relativistic kinematics being moved to the problems and replaced by a discussion on the electromagnetic Lagrangian. Materials on transition and collision radiation and multipole fields were modified. 117 new problems were added.