Armillary spheres are used to study the sky and the celestial coordinate system.
Miniature representations of the earth, moon, and planets in the form of terrestrial globes, terrain models and armillary spheres have a long history.
Caspar Vopel - Armillary SphereThe photo to the right is an armillary sphere made by Caspar Vopel (1511-1561), a German mathematician and geographer. It is a small manuscript terrestrial globe housed within a series of eleven interlocking armillary rings produced in 1543 by Caspar Vopell. Vogel depicts North American and Asia as one land mass, a common misconception of the time.
This armillary sphere, with its interlocking rings illustrated the circles of the sun, moon, known planets, and important stars as well as the signs of the zodiac and is a model of the Ptolemaic or earth-centered cosmic system. Ironically, the globe was constructed in the same year that Nicholas Copernicus (1473-1543) published his revolutionary Copernican System with the sun as the center of the solar system.
The Purpose of the Armillary SphereA model demonstrates how something works. One of the first models ever made was the armillary sphere, supposedly a model of the universe. By moving the armillary rings, you could demonstrate how the stars moved. However, early models had the Earth at the center of the universe. Like any model, armillary spheres were "modified" or changed with new discoveries.
Early History of the Armillary SphereSome sources credit Greek philosopher Anaximander of Miletus (611-547 B. C.) with inventing the armillary sphere, others credit Greek astronomer Hipparchus (190 - 120 BC), and some credit the Chinese.
Armillary spheres first appeared in China during the Han Dynasty (206 B.C.-220 A.D.). One early Chinese armillary sphere can be traced to Zhang Heng, an astronomer in the Eastern Han Dynasty (25 A.D.-220 A.D.).
The exact origin of armillary spheres cannot be confirmed. However, during the Middle Ages armillary spheres became widespread and increased in sophistication.
Martin BehaimThe first globe was made by German map-maker Martin Behaim in 1492.
Martin Behaim's Globe - 1492
James WilsonAmerica's first commercial globe maker, James Wilson (17631855), who was largely self-taught in geography and the techniques of engraving and globe construction, constructed his first globe in 1810, determined to produce globes that equaled those then being imported from England.
James Wilson Photo of Globes
James Wilson's American Globes - Newspaper Article