Geocentric model the coordinate system in order to predict the motions of planetary bodies, though doing so may make calculations easier to perform or interpret. A geocentric coordinate system can be more convenient when dealing only with bodies mostly influenced by the gravity of the Earth (such as artificial satellites and the Moon), or when calculating what the sky will look like when viewed from Earth (as opposed to an imaginary observer looking down on the entire solar system, where a different coordinate system might be more convenient). The Ptolemaic model of the solar system held sway into the early modern age;
Central High School (Pueblo, Colorado) and an outlying building used as a gym and school meeting area. It was built in 1906. The foyer features right-facing swastikas set into the tile floor. The original Central High School building on Pitkin Avenue (later used as an elementary school) was built of pink rhyolite; the "Stone Schoolhouse" was added to the National Register of Historic Places in 1979. Central first opened in 1883, and in 1886 graduated its first class of nine students. In 1889 Central introduced vocational education into its curriculum, making the district the first west of the Missouri River to introduce what was then