... system of dynamics,iscloselyconnectedwithourinterpretation of the greatprinciple of the Conservation of Energy, and itsfailure woulddeprivethatprinciple of much of itsmeaning.Accordingtothatprinciple the sum of the kinetic and potentialenergies of asystemisconstant;letus ... of theseparticlesisdueto the ethergrippedbytheirlines of force.Iflines of electricforcegrip the ether, then,sincewaves of light, accordingto the Electromagnetic Theory of Light,are waves of electricforcetravellingat the ... of electricforcetravellingat the rate of 180,000milespersecond, and as the lines of electricforcecarrywiththemsome of the ether,awave of lightwillbeaccompaniedby the motion of aportion of the ether in the direction in which...