High-level monograph focuses on an explicit treatment of the principle of general covariance as applied to electromagnetics, examining—among other subjects—the natural invariance of the Maxwell equations, general properties of the medium, nonuniformity, anisotropy and general coordinates in three-space, reciprocity and nonreciprocity, and matter-free space with a gravitational field. Of value to anyone interested in classical physics and to graduate students with a background in electromagnetic theory. 1962 ed.