Robert Hamill Nassau, an American Presbyterian missionary to the Ogowe region which later became Gaboon in West Africa in the 19th Century, was Albert Schweitzer’s predecessor in Lambaréné.
Robert Hamill Nassau is known today as the author of the great book Fetichism in West Africa. But his life and the rest of his work has been not been studied much. The Rev. Ray W. Teeuwissen who was also a Presbyterian missionary “discovered” Nassau by accident and devoted his Master’s thesis to him in 1976 and explains why this great man is largely unknown.
Robert Hamill Nassau was a remarkable man.
Born to a family of ministers, having decided to become a missionary, Nassau studied medecine after having studied theology in order to be able to survive.  
As a linguist, he wrote primers for African dialects, in particular the Fang language.
As a scientist, he helped researchers by sending samples of African plants to the US and the first complete skeleton of a gorilla.
He welcomed into his home Savorgnan de Brazza who considered him a fellow explorer.
He also took photographs, some of which are shown here.  
His two wives died in Africa but his daughter was the first white child to be born in Equatorial Africa.
Robert Hamill Nassau
Name: Nassau
First Name: Robert Hamill
Date of Birth: 11 Oct 1835
Place: Easton, Penn, USA
Education: Theology, Medecine
Profession: Pioneer Missionnary to West Africa
Date of Death: 6 May 1921
Place of Death: Philadelphia
taken by RH Nassau
Robert Hamill Nassau by
Ray W. Teeuwissen