The drawings relate to the maintenance of, alterations to, and additional construction work for, the canal. Most drawings date from the 1850s and 1860s, a few date from the 1820s, one (of a swing bridge at Weedon Depot) is dated 1806. Many drawings are of particular interest being of bridges over the canal which were being built by its rival as a freight channel, the rapidly expanding railway. Many bear the signature of J[esse] Cherry (Company engineer, Northern District), although a few bear the name John Cherry or James Cherry. Possibly they were put together by Cherry as a collection relating to work he had supervised. They include several drawings of cranes and a notable drawing of the pumping engine for one of the summit reservoirs.