John B. Alden, Alden's Handy Atlas of the World
“ Free commerce, in its widest sense, has been established in the basin of the Congo, and for a distance of 360 miles along the Atlantic. In this territory, no import duties can be levied for twenty years, and the Powers reserve the right to decide if freedom of entry shall be maintained beyond that period. The principal articles for export are said to be palm oil, ivory, rubber, gum copal, ground nuts, orchilla weed and cam-wood; principal imports are textiles, spirits, tobacco, guns and powder. ”
