For thirty years or more the expressions “Correlation of the Physical Forces” and “The Conservation of Energy” have been common, yet few persons have taken the necessary pains to think out clearly what mechanical changes take place when one form of energy is transformed into another. Since Tyndall gave us his book called Heat as a Mode of Motion neither lecturers nor text-books have attempted to explain how all phenomena are the necessary outcome of the various forms of motion. In general, phenomena have been attributed to forces—a metaphysical term, which explains nothing and is merely a stop-gap, and.
