Elasticity and electromagnetism. Part 1: The Coulomb gauge
  The Maxwell's electromagnetic equations are isomorphic to the motion equation of a linear elastic continuum which is hard to compression though liable to shear deformation. The Coulomb gauge expresses the medium incompressibility. The magnetic vector potential corresponds to the medium velocity. The pressure stands for the electrostatic potential. The electric field is modeled by an external force whose origin is beyond the elastic model. The electric charge corresponds to a medium defect which produces the perturbation 1/r of the pressure field . The defects interact with each other due to the dilatation center in the core of the inclusion. 
V.P. Dmitriyev