Maxwell's stress equation for electrostatics identifies a tensile stress in the direction of the electric field and a pressure normal to this direction. For an isolated, spherically symmetric static charge distribution, Maxwell's stress equation may be recast to eliminate the stress normal to the electric field and establish a stress only aligned with the electric field. The remaining stress is identified as an external omnidirectional Poincaré stress, inwardly directed towards the charge distribution. The Poincaré stress is modeled as a mean valued, continual exchange of bosons between the charge distribution and the distant matter of the universe. For two separated, spherically symmetric static charge distributions, Maxwell's stress equation may be recast to develop a line stress that only exists on the straight path between the two charge distributions. The line stress is identified as a Coulomb stress modeled as a mean valued, continual exchange of photons back and forth between two like-charge distributions.

Capacitance is defined for electrostatics as the ratio of charge to voltage. Even for the simple case of two parallel discs in free space, there are over 25 associated capacitance terms identified in this work. Therefore, the simple free space disc capacitor has some underlying complexities. The various capacitance terms associated with two discs (or generally for two conductors in free space) are introduced and their interrelations defined. In particular, the relationships between the potential coefficient matrix, capacitance matrix and the Π and T capacitance networks are given in detail. Finally, the capacitance of two oppositely charged discs in free space is analysed for all separation distances. A collective work not available elsewhere is conveyed for the many capacitances and capacitance terms of two parallel discs in free space.

Maxwell's stress equation for electrostatics identifies a tensile stress in the direction of the electric field and a pressure normal to this direction. For an isolated, spherically symmetric static charge distribution, Maxwell's stress equation is manipulated using a variant of Stokes' Theorem. The recast stress equation eliminates the stress normal to the electric field and establishes a stress only aligned with the electric field. For two separated, spherically symmetric static charge distributions, Maxwell's stress equation is also manipulated using a variant of Stokes' Theorem. The recast stress equation develops a line stress that only exists on the straight path between the two charge distributions. The analysis and manipulation of Maxwell's stress equation provides some insight into electrostatic stresses and establishes additional tools for the electrical engineer when analyzing electrostatic system stresses.

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The equivalence of the Ampère and Grassmann (Biot–Savart/Lorentz) current element force formulas is well established. However, when the magnetostatic potential energy corresponding to these force formulas is evaluated, the formulas are found to be nonequivalent. The historical current element force formulas are first presented. The magnetostatic potential energy corresponding to these historical current element force formulas are then analysed. The end result establishes the Grassmann and Neumann current element force formulas as the only commonly referenced formulas giving the correct magnetostatic potential energy for circuital currents.