GEO LOCATION
The staircase is referenced as a location within the house, relevant to Scrooge's movements and the narrative description.
STAIRCASE
You may talk vaguely about driving a coach and six up a good old flight of stairs, or through a bad young Act of Parliament; but I mean to say you might have got a hearse up that staircase, and taken it broadwise, with the splinter-bar towards the wall, and the door towards the balustrades: and done it easy.