In 1881, cooperating with the Rev Thomas J. Comber and others, he established a chain of missions at Musuko, Vivi, Isangila, Manyanga, and other points, and in 1884, in a small steam vessel, he explored the Congo to the equator. He established headquarters at Arthington, near Leopoldville, in 1884, and launched on Stanley Pool a river steam vessel, the "Peace", in which he explored the Kiva, the Kwango, and the Kasai rivers, discovered the Ruki, or Black River, and ascended the Mubangi for 200 miles (320 km) to Grenfell Falls, at lat. 4° 40' N.