Аннотация:In this work, the methods of continuum mechanics are transferred to the four-dimensional continuum, in which the normalized four-dimensional vector-potential of the electromagnetic field is playing the role of 4D-displacement. Classical electrodynamics is presented as a theory of elasticity of 4D-medium with anti-symmetric stress tensor, where Faraday equations are the equations of compatibility, and Ampere equations are the equations of equilibrium. It is shown, that for the considered continuum, the tensor of the fourth rank modules in defining ratios formally allows not only anti-symmetric structure. Uncertain symmetry of electromagnetic "stresses" allows to build a version of the non-anti-symmetric electrodynamics and to predict new effects of the interaction of electromagnetic field with spatially-isotropic material: dynamic, thermal and striction.