Letter from [Hugh Longbourne] Callendar, Saundersfoot, South Wales, to [Robert William Frederick] Harrison Callendar recommends Professor Poynting for the Royal Medal 'in recognition of his contribution to the theory of the electromagnetic field and radiation, and his researches on the measurement of gravity. He proposes Principal Griffith's for the Rumford Medal 'in recognition of his work on the mechanical equivalent of heat and on [?] heat of evaporation from electrical themometry'. 16 July 1904