Drummond made many detailed studies for his great painting showing the execution of Captain Porteous. Although he relegated the main action to the background of the picture, he was careful to ensure that the foreground figures helped to communicate the story as described in Sir Walter Scott?s `Heart of Midlothian?. In the novel, Scott mentions that ladies in sedan chairs were stopped by rioters. Sedan Chairs were common in Edinburgh, as they were able to negotiate the many narrow closes that a carriage could not. The chairs-bearers were normally Highlanders who had moved south in search of work. They were distinguished by their tartan uniforms. In this drawing, Drummond sketched in the sullen face of the stooped chair-bearer, as he peers around the door at his refined passenger.