Unjustly neglected classic sets forth the fundamentals of thermodynamics clearly and simply enough to be understood by a beginning student, yet with enough subtlety and depth of thought to appeal also to more advanced readers. Maxwell goes on to elucidate the fundamental ideas of kinetic theory, and—through the mental experiment of "Maxwell’s demon"—points out how the Second Law of Thermodynamics relies on statistics. New introduction and notes by Peter Pesic.