The volume contains outwards copy correspondence sent by, Arthur Riches (1864-1927), the Chief Collector of the Humber Conservancy Board. The main subject matter is the collection of shipping and registration dues by the Board, and issues and queries arising as a result. Other topics covered include the Board's accounts, payments to/from the Board, the collection of fees for pilot licenses, the collection of rent, taxation matters, and routine office correspondence.

The main recipients are the owners of shipping/rivercraft, government officials, and officials, officers, and employees of the Board. An index of recepients can be found at the front of the volume.