What is the instrument of the north and south?

The "instrument of the north and south" typically refers to the compass, which is used for navigation by indicating cardinal directions: north and south. In a broader context, it could also symbolize the geographic and cultural divides between the northern and southern regions of various countries, such as the United States during the Civil War. In literature and discourse, this phrase might evoke themes of division, direction, and the quest for understanding or unity between contrasting regions.