De revolutionibus orbium coelestium divided into six "books" (sections or parts), following closely the layout of Ptolemy's "Almagest" which it updated and replaced: Copernicus argued that the universe comprised eight spheres. The outermost consisted of motionless, fixed stars, with the Sun motionless at the center. The known planets revolved about the Sun, each in its own sphere, in the order: Mercury, Venus, Earth, Mars, Jupiter, Saturn. The Moon, however, revolved in its sphere around the Earth. What appeared to be the daily revolution of the Sun and fixed stars around the Earth was actually the Earth's daily rotation on its own axis. Copernicus adhered
Paris in the 16th century the 16th century, Paris became first in Europe in book publishing. In 1530, Françis I created a new faculty at the University of Paris with the mission of teaching Hebrew, Greek and mathematics. It became the "Collège de France". In 1540, the Jesuit order established its first schools in Paris. In 1549, the first textbook of the French language, "Defense et illustration de la langue Française", by Joachim de Ballay, was published. Francis I died in 1547. His son, Henry II, made his official entrance into Paris in 1549 with a lavish procession and ceremony; the first Renaissance fountain in