“The axis of a sphere is a line passing through the center and intersecting at the farthest points on both sides of the circumference of the sphere. Around this axis the spheres rotate much like the wheel of a wagon about the axle, which in the case of the sphere is a smoothly rounded pole [the axis being the diameter of the circle itself]." (

__- Hessler 2008)__*Cosmographiae introductio*, chap. II