Letter from Oliver [Joseph] Lodge, Mariemont, Edgbaston, to [Joseph] Larmor He has never been sure of [John Henry] Poynting's theorem is part of [James Clerk] Maxwell's theorem or not. It seems deducible from Maxwell's equations, but seems beyond what he taught. He asks what Larmor thinks of the matter: he knows that Poynting gave pictorial representations of the transmission of energy in varieties of electric circuits, but he cannot believe that the theorem itself is more than anything already in Maxwell. 8 May 1915