The armillary sphere consists of two major components, the sphere and the stand, as shown in the figure below:
The heart of the armillary sphere is the sphere itself, which was often made and used alone.
The various components of the sphere are as follows:
1. The axis, corresponding to the rotational axis of the earth (represented by the green malachite sphere at the center).
2.
3. The Arctic circle, the lowest latitude at which the sun will become invisible in the north during winter.
The Stand serves three purposes: a) it is decorative, b) it serves as a memory aid to place the sun in the proper astrological house for a given date, and c) it allows one to set the inner sphere to a given latitude to show times of sunrise and sunset etc.
