This picture is cropped from the opening illustration to Dickens' Our Mutual Friend. It's the original illustration by Marcus Stone and was thus drawn in around 1864/1865, and the action depicted is described as taking place between Southwark and London Bridges. My question is "what is that curious Shard-like structure on the horizon?" I'm afraid I can't make any sense of it.
That thing looks to be a hoisting tripod, called sheers or sheer-legs