Possible Clues:

• Here they drew the line at nothing!
• Circular line converted to square (but not initially)
• One of the great circles
• Meeting of two halves is unusually quorate
• A torque, twisting, that has zero latitude
• Peer briefly takes to writing to one with no latitude?
• A band going across Africa and many other places
• European queen turning round in great circle
• Division between Northern and Southern hemispheres
• Ring round globe