Spencer Jones 's astronomical work extended over a range of subjects . He specialised in positional astronomy , particularly the motion and orientation of the Earth in space . He also studied the motions of stars . He travelled to Minsk in Eastern Europe in 1914 to observe a total solar eclipse , departing during peacetime but returning after the start of the First World War . His activities at the observatory were disrupted by the war , when he worked temporarily for the Ministry of Munitions , particularly on optics
total solar eclipse
Solar eclipse of August 21, 1914
Harold Spencer Jones