James Clerk Maxwell (1831-1879), first Cavendish Professor of Physics at Cambridge, made major contributions to many areas of theoretical physics and mathematics, not least his discoveries in the fields of electromagnetism and of the kinetic theory of gases, which have been regarded as laying the foundations of all modern physics. This work of 1881 was edited from Maxwell's notes by a colleague, William Garnett, and had formed the basis of his lectures. Several of the articles included in the present work were also included in his two-volume Treatise on Electricity and Magnetism (1873), also reissued in this series. The preface indicates that the two works were aimed at somewhat different audiences, the larger work assuming a greater knowledge of higher mathematics. Maxwell had also modified some of his methodology, and hoped to encourage the reader to develop an understanding of concepts relating to electricity.