Astronomical Models
For as long as mankind has been curious about his relation to the heavens, he has attempted to depict that relationship in concrete form. During the Renaissance, the knowledge of astronomy and the development of arts and crafts combined and reached a new height in astronomical models. The terrestrial globe was the earliest three-dimensional astronomical model, and the armillary sphere was its logical extension. In an effort to depict the equator, the orbit of the moon and other information, the globe was enclosed within a cage of rings with inscribed increments. 
The tellurium used a smaller globe to represent the earth, with a model of the moon in orbit around it. Using a train of gears, the moon could be made to circle the earth and even show its progression of phases throughout the lunar cycles. Later, more advanced telluria had a model sun as well, with both earth and moon in rotation around it. The orrery was a further evolution of the tellurium, and included all of the known planets. The mechanisms used to synchronize the planets and moons were the most complicated mechanical objects of their day and were so expensive that only the aristocracy could afford them. Thankfully, since they were so expensive and highly prized, many of them have survived and are now safely in museums. 
My favorite astronomical model has to be the solar system constructed between 1774 and 1781 by a Friesian man named Eise Eisinga, in the northern Netherlands town of Franeker. The local populace was being frightened by a clergyman who claimed that the earth would soon be destroyed by a planetary collision. In order to prove to the townsfolk that they had nothing to fear, Eisinge constructed a remarkably sophisticated working model of the solar system. It was so large that it took up the entire ceiling of the main room of his house, and the clockwork mechanism filled the attic. When the local people were able to examine the model and see the way that celestial bodies moved in their orbits, they were reassured. Once again, rational thought triumphed over superstitious fear. Amazingly, the orrery is still fully functioning! It and the house have been preserved intact as a museum and a tribute to this remarkable man. For more information on Eise Eisinga Planetarium: |
