Geocentric model and planets were holes in invisible wheels surrounding Earth; through the holes, humans could see concealed fire. About the same time, Pythagoras thought that the Earth was a sphere (in accordance with observations of eclipses), but not at the center; they believed that it was in motion around an unseen fire. Later these views were combined, so most educated Greeks from the 4th century BC on thought that the Earth was a sphere at the center of the universe. In the 4th century BC, two influential Greek philosophers, Plato and his student Aristotle, wrote works based on the geocentric model.
Iron Mountain Central Historic District Iron Mountain Central Historic District The Iron Mountain Central Historic District is a historic district, broadly located between Fleshiem and C Streets and between Iron Mountain and Stockbridge Avenues in Iron Mountain, Michigan. The district covers the city's central business district and adjacent areas. It is primarily commercial, but also contains the historic county courthouse complex, and school, library, and church buildings. It was listed on the National Register of Historic Places in 2013. Lake Superior Iron Ranges]] A major iron ore deposit was discovered near what is now Iron Mountain in 1878/79; the first ore from the first area