When conscription was introduced in Britain on 2 March 1916 , Eddington intended to apply for an exemption as a conscientious objector . Cambridge University authorities instead requested and were granted an exemption on the ground of Eddington 's work being of national interest . In 1918 , this was appealed against by the Ministry of National Service . Before the appeal tribunal in June , Eddington claimed conscientious objector status , which was not recognized and would have ended his exemption in August 1918 . A further two hearings took place in June and July , respectively . Eddington 's personal statement at the June hearing about his objection to war based on religious grounds is on record . Astronomer Royal , Sir Frank Dyson , supported Eddington at the July hearing with a written statement , emphasising Eddington 's essential role in the solar eclipse expedition to Príncipe in May 1919 . Eddington made clear his willingness to serve in the Friends ' Ambulance Unit , under the jurisdiction of the British Red Cross , or as a harvest labourer . However , the tribunal 's decision to grant a further twelve months exemption from military service was on condition of Eddington continuing his astronomy work , in particular in preparation for the Príncipe expedition . The war ended before the end of his exemption
solar eclipse
Solar eclipse of May 29, 1919
Arthur Eddington