G. G. Stokes and Lord Kelvin helped bring about conceptual and institutional changes that transformed the science of physics. Indeed, they and their Victorian colleagues constituted one of the most significant groups of scientists in the whole history of science. This collection of letters was first published in 1990, and provides, therefore, invaluable insight and information for a period of major historical importance. Stokes and Kelvin corresponded for over fifty years as professors in Cambridge and Glasgow, respectively, thus amassing what is easily the largest extant correspondence between two Victorian physicists. The letters range widely over the people, ideas, and institutions of the age. They illuminate the histories of Cambridge and Glasgow Universities and the Royal Society of London, for example, as well as developments in electromagnetism, hydrodynamics, elasticity, optics, and X-rays. The editor's introduction describes the context of the pair's careers, while guiding the reader into their correspondence.