SEARCH Articles Figures Tables A perpetual-motion machine of the second kind Perpetual motion limits Perpetual motion machine of the second Perpetual motion machine, second kind Perpetual motion machines of the first kind Perpetual motion machines of the second kind Perpetual motion of second kind Perpetual motion of the second kind Perpetual motion, first kind Perpetual-motion machines Perpetuity Theoretical Limits on Perpetual Motion Kelvins and Clausius Principles