"a Company for trade on that river"

This was the Société Anonyme Belge pour le Commerce du Haut-Congo (Belgian Limited Company for Trade on the Upper Congo), the Belgian trading company which employed Conrad during his time in the Congo. A subsidiary of Albert Thys' Compagnie du Congo pour le Commerce et l'Industrie (CCCI), it was created in December 1888 when the CCCI merged with the Sanford Exploring Expedition. The Société Anonyme Belge was administered in Brussels but maintained a number of stations all over the Congo, especially along its major waterways.