The volume contains outwards copy correspondence sent by, Harry Colquhoun (b. 1890), 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.