Moore that the sandstone ridges which here bound the trough have been recently elevated, and have been cut through by the Lukuga during the process.
C. Hore and other early travellers, but has been more systematically studied by Mr Moore (during expeditions of 1896 and 1898-99) and Dr W.
The Lukuga was reported blocked by a bar about 1897, but a certain amount of water was found flowing down by Mr Moore in 1899; while in 1901 Mr Codrington found the level 4 or 5 feet higher than in moo, the outlet having again silted up. A continued rise was also reported in 1907.
Mr Hore often failed to find bottom with a line of 168 fathoms. The French explorer, Victor Giraud, reported 647 metres (about 350 fathoms) off Mrumbi on the west coast, and Moore depths of 200 fathoms and upwards near the south end.