Letter from J H [John Henry] Poynting, 10 Ampton Road, Edgbaston, Birmingham, to [Joseph] Larmor Poynting commences: 'It may be my baby but you are its godfather'. He will try to make out the solution along the lines Larmor recommends, but has undertaken to write a booklet for CUP [Cambridge University Press] so the problem will have to wait for now. 16 January 1912