What is the name of the imaginary line that divides the celestial globe into two hemispheres?

The imaginary line that divides the earth into in this case the north and south hemispheres is called the Equator and it passes through Ecuador and actually Ecuador is the Spanish word for Equator. The French explorer La Condamine spent 10 years in Ecuador studying the equator and determined the oblate spheroid shape of the world.

Early in the story when tom finds an indian skull in the woods which he kicks in temper. the devil then makes his appearance and, as tom surveys him, he notices that the devil is neither "negro" nor "indian." in fact, he has a "swarthy" complexion and is "begrimed with soot."