Wyllie’s marine paintings capture the busy working life of the Thames in its heyday when London was the biggest and richest port in the world. This scene has been identified as the Pool of London below London Bridge, looking towards the dome of the Old Royal Naval College in Greenwich.

The title of the picture is evoked by the contrast between the dirt and toil of the men working on the coal barge and the implied wealth that is generated when coal is converted into steam for industry.