‎"MAXWELL, JAMES CLARK. - THE INTRODUCTION OF THE ""ELECTRICAL FORMULATION"" OF THE ELECTROMAGNETIC THEORY OF LIGHT.‎
‎On a Method of making a Direct Comparison of Electrostatic with Electromagnetic Force"" with a Note on the Electromagnetic Theory of Light. (Read June 18, 1868).‎

‎(London, Taylor & Francis, 1869) Large 4to. Without wrappers. Extracted from ""Philosophical Transactions of the Royal Society of London."", Vol. 158. Maxwell's paper: pp. 643-657. Clean and fine, wide margins.‎

Reference : 42029

‎First appearance of this major paper on electromagnetic dynamics, in which Maxwell improves the groundbreaking equations he had set forth in his famous paper of 1865, the ""A dynamical Theory of Electro-Magnetic Fields"". In the paper offered here, he for the first time proposed to base the electromagnetic theory of light solely on 2 equations. The paper is one of Maxwell's 5 most importent contributions to electromagnetism.""Formulas for the forces between moving charged bodies may indeed de derived from Maxwell's equations, but the action is not along the line joining them and can be reconciled with a dynamical principle only by taking into account the exchange of momentum with the field. Maxwell remarked that the equations might be condensed, but ""to eliminate a quantity which expresses a useful idea would be rather a loss than a gain in this stage of our enquiry."" he had in fact simplified the equations in his fifth major paper, the short, but importent ""Note on the Electromagnetic Theory of Light."" (1868), writing them in an integral form without the function A, based on four postulates derived from electrical experiments. This may be called the electrical formulation of the theory, in contrast with the original dynamical formulation."" (C.W.F. Everitt in DSB).‎