[1] He joined the civil service in 1899, initially working in the Lands & Survey Department, before becoming Chief Accountant in 1912 and an inspector in 1915.

[4] In 1935 he was appointed Acting Administrator, succeeding Herbert Ernest Hart.

Turnbull was a popular figure in Samoa, and a petition was sent to the New Zealand government requesting his appointment.

[2] He remained in office until 1946, when he retired and was replaced by Francis William Voelcker.

[6] He was appointed a Knight Commander of the Order of the British Empire in the 1946 New Year Honours.