He is best known for his work in China, where he, as an assistant to Johan Gunnar Andersson, discovered a fossil tooth of the Peking Man in 1921 at the Dragon Bone Hill, although he did not disclose it until 1926 when he published it in Nature after an analysis by Davidson Black.
Najpoznatiji je po radu u Kini gdje je kao pomoćnik švedskom znanstveniku Johanu Gunnaru Anderssonu otkrio fosilni zub pekinškog čovjeka 1921. na Brdu zmajeve kosti, iako to nije otkrio sve do 1926. kad ga je objavio u Nature poslije analize Davidsona Blacka.