Armillary Globes and Spheres. Way back in the 15th and 16th century the armillary globe was used by the Portuguese mariners. It was a useful navigational instrument. It is actually one of the oldest astronomical instruments. In the form of a skeletal sphere with up to nine rings. These rings represent the great circles of the heavens. Perhaps because of their complex design. These instruments have become items of fashion. Used within the house and around the garden. They are as used focal points and to make a statement.