16th-century astronomy. Artwork of an armillary sphere, published in Paris in the 1547 edition of Sphaera, an astronomical work by the 5th-century Greek philosopher Proclus (412-485). An armillary sphere is an astronomical device that shows the circles of the celestial sphere surrounding the Earth (centre). Here, the astrological signs of the zodiac mark the circle of the ecliptic, inclined at an angle to the celestial equator, which corresponds to Earth's equator. The North and South Poles, the Tropics of Capricorn and Cancer, and the Arctic and Antarctic Circles are also shown. The Sun and Moon are shown at top.