イギリス領東アフリカ
He worked for a commercial company in German East Africa (1893–96) and in 1897 he was appointed assistant collector in the British East Africa Protectorate. He wrote pioneering works on the Maasai (1905) and the Nandi people (1908). During his time in East Africa he took part in numerous expeditions including the Uganda Mutiny (1897–98) and the Jubaland Expedition (1900–01). Between 1901 and 1907 he worked as Secretary to the East Africa Protectorate administration, and was Secretary for Native Affairs between 1907–1913.