Who is the load stone rock in a tale of two cities?

Ernest Defarge described as the loadstone rock in Chapter 24

'A loadstone is a magnet, specifically one consisting of magnetic oxide of iron. The Word "load-stone," meaning literally "way-stone," comes from the use of magnets in marine navigation (Oxford English Dictionary); figuratively, a loadstone is an object that attracts. In Dickens' use of term - in the title of this chapter, and in later references within the chapter - he is alluding to a particular loadstone in the Arabian Nights. In the story called "The Third Calender's Tale," Ajib, a prince and a calender (a calender is a Persian or Turkish mendicant dervish [OED]) describes a voyage of discovery in which his ship was irresistibly drawn to an enormous Loadstone Rock. The Rock, exerting such a force on the ship as to pull all the nails out of its structure and sink it, effectively marooned the calender on its shores. It was surmounted, however, with a bronze statue of a horse and rider; and Ajib, receiving advice (in a dream) that he should shoot the statue with a bronze bow he had found, did so and was liberated: The statue disintegrated, and Ajib was borne off in a bronze boat to further adventures (summarized in Sanders 125-6; Burton, vol.1, 139-61).'