Armillary Sphere

             An armillary sphere is a globe made of movable , concentric rings that depict such things as horizon, meridian, equator, tropics and polar circles. The earliest known complete armillary is attributed to the Greeks in the early second century A.D . Ptolemy created one to promote his geocentric vision of the cosmos. In 1543, German mathematician Caspar Vogel constructed an armillary sphere that supported Ptolemy's theory. In the same year, Copernicus published his revolutionary treatise placing the sun at the center of the solar system.
        Afterwards Ptolemaic and Copernican spheres where exhibited together to display the differences between the two versions of the cosmos.