Armillary sphere

Manuel I of Portugal, for example, took it as one of his symbols where it appeared on his standard, and on early Chinese export ceramics made for the Portuguese court.

The exterior parts of this machine are a compages [or framework] of brass rings, which represent the principal circles of the heavens: In the north pole of the ecliptic is a nut b, to which is fixed one end of the quadrantal wire.

In the south pole of the ecliptic is a pin d, on which another quadrantal wire is situated, with a small moon Ζ upon it, which may be moved around by hand.

The globe assembly is supported on a pedestal N, and may be elevated or depressed upon the joint O, to any number of degrees from 0 to 90 by means of the arc P, which is fixed in the strong brass arm Q.

[4] During the Western Han dynasty (202 BC – 9 AD) additional developments made by the astronomers Luoxia Hong (落下閎), Xiangyu Wangren, and Geng Shouchang (耿壽昌) advanced the use of the armillary in its early stage of evolution.

[3] The world's first water-powered celestial globe was created by Zhang Heng, who operated his armillary sphere by use of an inflow clepsydra clock.

However, it was the Tang Chinese astronomer, mathematician, and monk Yi Xing in the next century who would accomplish this addition to the model of the armillary sphere.

In 723 AD, Yi Xing (一行) and government official Liang Ling-zan (梁令瓚) combined Zhang Heng's water powered celestial globe with an escapement device.

[6] The famous clock tower that the Chinese polymath Su Song built by 1094 during the Song dynasty would employ Yi Xing's escapement with waterwheel scoops filled by clepsydra drip, and powered a crowning armillary sphere, a central celestial globe, and mechanically operated manikins that would exit mechanically opened doors of the clock tower at specific times to ring bells and gongs to announce the time, or to hold plaques announcing special times of the day.

[11][12][13][14][15] Names of this device in Greek include ἀστρολάβος astrolabos and κρικωτὴ σφαῖρα krikōtē sphaira "ringed sphere".

Before the advent of the European telescope in the 17th century, the armillary sphere was the prime instrument of all astronomers in determining celestial positions.

[17] It consisted of at least three rings, with a graduated circle inside of which another could slide, carrying two small tubes positioned opposite each other and supported by a vertical plumb-line.

[1][17] Persian and Arab astronomers such as Ibrahim al-Fazari and Abbas Ibn Firnas continued to build and improve on armillary spheres.

Jang Yeong-sil, a Korean inventor, was ordered by King Sejong the Great of Joseon to build an armillary sphere.

The Honcheonsigye, an armillary sphere activated by a working clock mechanism was built by the Korean astronomer Song Iyeong in 1669.

[22] Further advances in this instrument were made by Danish astronomer Tycho Brahe (1546–1601), who constructed three large armillary spheres which he used for highly precise measurements of the positions of the stars and planets.

Renaissance scientists and public figures often had their portraits painted showing them with one hand on an armillary sphere, which represented the zenith of wisdom and knowledge.

The armillary sphere survives as useful for teaching, and may be described as a skeleton celestial globe, the series of rings representing the great circles of the heavens, and revolving on an axis within a horizon.

An artwork-based model of an Armillary sphere has been used since the March 1, 2014 to light the Paralympic heritage flame at Stoke Mandeville Stadium, United Kingdom.

The sphere includes a wheelchair that the user can rotate to spark the flame as part of a ceremony to celebrate the past, present and future of the Paralympic Movement in the UK.

In the end of the 15th century, the armillary sphere became the personal heraldic badge of the future King Manuel I of Portugal, when he was still a Prince.

The intense use of this badge in documents, monuments, flags and other supports, during the reign of Manuel I, transformed the armillary sphere from a simple personal symbol to a national one that represented the Kingdom of Portugal and in particular its Overseas Empire.

In 1815, when Brazil gained the status of kingdom united with that of Portugal, its coat of arms was formalized as a golden armillary sphere in a blue field.