Finberg described the subject as ‘Lock gates’ but Turner seems to show a large sluice outfall. The figures to the left give the structure scale. In the background are what appear to be crags or a quarry face. Identifiable sketches originally succeeding this in the sketchbook are at Cassiobury near Watford, and given the barges mentioned in the inscription this might be a subject on the Grand Union Canal in the Colne Valley near Rickmansworth.
The Grand Union was completed in 1803 and linked London with Birmingham and the north of England. The coal could have come from the maritime coalfields of the North-West or North-East, or possibly from the Midlands. In this same sketchbook, Turner sketched coal setting out from the coal port of Whitehaven.
Blank, except for an inscription (?by one of the Executors of the Turner Bequest) in pencil ‘Sched 154.17’. 154 appears to be a mistake for 164. The majority of leaves are similarly inscribed with the schedule number (usually given correctly as 164) plus the page number in the sequence. This numbered sequence runs counter to that given by Finberg and appears to be original (see Introduction, and notes to D12244; Turner Bequest CLV 4a).