Armillary sphere in the context of "Yi Xing"

Su Song (Chinese: 蘇頌; Pe̍h-ōe-jī: So͘ Siōng, 1020–1101), courtesy name Zirong (Chinese: 子容; Pe̍h-ōe-jī: Chú-iông), was a Chinese polymathic scientist and statesman who lived during the Song dynasty (960–1279). He excelled in numerous fields including but not limited to mathematics, astronomy, cartography, geography, metallurgy, mechanical engineering, hydraulic engineering, poetry, and statesmanship.

Su Song was the engineer for a hydro-mechanical astronomical clock tower located in Kaifeng. It employed an early escapement mechanism. The escapement mechanism of Su's clock tower was invented by the Tang dynasty Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, however Su's armillary sphere was the first to utilize a mechanical clock drive. Su's clock tower also featured the oldest known endless power-transmitting chain drive, called the tian ti (天梯), or "celestial ladder", as depicted in his horological treatise. The clock tower had 133 different clock jacks to indicate and sound the hours. The clock was dismantled by the invading Jurchen army in 1127 AD, and although attempts were made to reassemble it, the tower was never successfully reinstated.

Astronomical rings (Latin: annuli astronomici), also known as Gemma's rings, are an early astronomical instrument. The instrument consists of three rings, representing the celestial equator, declination, and the meridian.

It can be used as a sun dial to tell time, if the approximate latitude and season is known, or to tell latitude, if the time is known or observed (at solar noon). It may be considered to be a simplified, portable armillary sphere, or a more complex form of astrolabe.

Pope Sylvester II (Latin: Silvester II; c. 946 – 12 May 1003), originally known as Gerbert of Aurillac, was a scholar and teacher who served as the bishop of Rome and ruled the Papal States from 999 to his death. He endorsed and promoted study of Moorish and Greco-Roman arithmetic, mathematics and astronomy, reintroducing to Western Christendom the abacus, armillary sphere, and water organ, which had been lost to Latin Europe since the fall of the Western Roman Empire. He is said to be the first in Christian Europe (outside of Al-Andalus) to introduce the decimal numeral system using the Hindu–Arabic numeral system.

In astronomy, a planisphere (/ˈpleɪ.nɪˌsfɪər, ˈplæn.ɪ-/) is a star chart analog computing instrument in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date. It is an instrument to assist in learning how to recognize stars and constellations. The astrolabe, an instrument that has its origins in Hellenistic astronomy, is a predecessor of the modern planisphere.The term planisphere contrasts with armillary sphere, where the celestial sphere is represented by a three-dimensional framework of rings.

The Beijing Ancient Observatory (traditional Chinese: 北京古觀象臺; simplified Chinese: 北京古观象台; pinyin: Běijīng Gǔ Guānxiàngtái) is a pretelescopic observatory located in Beijing, China. The observatory was built in 1442 during the Ming dynasty, and expanded during the Qing. It received major reorganization and many new, more accurate instruments from Europeans (Jesuits) in 1644.

As one of the oldest observatories in the world, the Beijing Ancient Observatory grounds cover an area of 10,000 square meters. The observatory itself is located on a 40 by 40 metres (130 ft × 130 ft) wide platform on the top of a 15 m (49 feet) tall brick tower, an extant portion of the old Ming dynasty era city wall that once encircled Beijing. Several of the bronze astronomical instruments are on the platform, and other armillary spheres, sundials, and other instruments are located nearby at ground level. It is operated as a museum in affiliation with the Beijing Planetarium.

The Song dynasty (Chinese: 宋朝; 960–1279 CE) witnessed many substantial scientific and technological advances in Chinese history. Some of these advances and innovations were the products of talented statesmen and scholar-officials drafted by the government through imperial examinations. Shen Kuo (1031–1095), author of the Dream Pool Essays, is a prime example, an inventor and pioneering figure who introduced many new advances in Chinese astronomy and mathematics, establishing the concept of true north in the first known experiments with the magnetic compass. However, commoner craftsmen such as Bi Sheng (972–1051), the inventor of movable type printing (in a form predating the printing press of Johannes Gutenberg), were also heavily involved in technical innovations.

The ingenuity of advanced mechanical engineering had a long tradition in China. The Song engineer Su Song, who constructed a hydraulically-powered astronomical clocktower, admitted that he and his contemporaries were building upon the achievements of the ancients such as Zhang Heng (78–139), an astronomer, inventor, and early master of mechanical gears whose armillary sphere was automatically rotated by a waterwheel and clepsydra timer. The application of movable type printing advanced the already widespread use of woodblock printing to educate and amuse Confucian students and the masses. The application of new weapons employing the use of gunpowder enabled the Song to ward off its militant enemies—the Liao, Western Xia, and Jin with weapons such as cannons—until its collapse to the Mongol forces of Kublai Khan in the late 13th century.

A monde, meaning 'world' in French, is an orb located near the top of a crown. It represents, as the name suggests, the world that the monarch rules. It is the point at which a crown's half arches meet. It is usually topped off either with a national or religious symbol, for example a cross in Christian countries.

In some cases, the crossed arches might relate this object to an armillary sphere representing the cosmic orb, as seems to happen with the crown of Pedro I of Brazil or, in a different way, with the serpent in the Rainbow Portrait of Queen Elizabeth I.