In the 17th century, it became associated with the Portuguese dominion of Brazil. 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. Representing Brazil, the armillary sphere became also present in the arms and the flag of the United Kingdom of Portugal, Brazil and the Algarves. When Brazil became independent as an empire in 1822, the armillary sphere continued to be present in its national arms and in its national flag. The celestial sphere of the present Flag of Brazil replaced the armillary sphere in 1889. An armillary sphere such as this one might well have been used for education, aiding understanding of the 3-dimensional geometry of the celestial sphere. This makes sense, as many medieval and early-modern texts in basic astronomy refer to or assume the use of armillaries as models of the heavens. Medieval illustrations even suggest that a 3-dimensional visual aid might well have been a necessary companion to texts on the celestial sphere, such as the 13th-century De sphaera by Sacrobosco, which was a widely used university textbook.

With the Earth as center, an armillary sphere is known as Ptolemaic. With the Sun as center, it is known as Copernican. [1] An armillary sphere can be turned into an armillary sundial by setting its celestial polar axis equal to the latitude of the sundial’s location and directed at the North Celestial Pole. The sphere’s Horizon ring is fixed parallel to the terrestrial horizon. And finally the meridian ring called the Solstitial Colure, which passes through the celestial poles and the two solstices, is rotated to the vertical position so as to coincide with the local meridian of the sundial’s location. Terminology of astronomical coordinate systems There is no evidence for the Hellenistic origin of the spherical astrolabe, but rather evidence so far available suggests that it may have been an early but distinctly Islamic development with no Greek antecedents." Christopher Cullen, "Joseph Needham on Chinese Astronomy", Past and Present, No. 87 (May, 1980), pp. 39–53 (45) The metal rings, usually made of brass or bronze, are referred to as armilla, which is Latin for bracelet. Armilla were prestigious armbands awarded to Roman soldiers for distinguished gallantry.

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. As a national symbol, the armillary sphere continued in use after the death of Manuel I. The Symonds papers are held by Winterthur Museum in the USA. With the Symonds papers is an album of photographs labelled ‘Furniture Sandridgebury No 1’. Symonds wrote a ‘Portrait of a Collector’ about Percival Griffiths, in Country Life, June 13, 1952. R W Symonds’ book ‘English Furniture from Charles II to George II’ (1929) is illustrated with items from the Sandridgebury collection. In the foreword Griffiths writes of his experience and philosophy as a collector. See also 'Intuitively Collected', by Simon Houfe, Country Life 27 December 1990. Museum numbers W.34-1939 to W.37-1938, a centre table, tripod table, armillary sphere and gate-leg table, were bought for the Museum by the National Art Collections Fund from the estate of Percival Griffiths (1861-1937). The choice was left to the Museum. A mirror, W.39-1938 was also given by his widow, Mrs Percival Griffiths, in his memory. Percival Griffiths, who lived at Sandridgebury, Hertfordshire, formed a collection of English furniture dating from the late 17th and early 18th century under the guidance of R.W. Symonds, the furniture historian and prolific writer on English furniture. Brashear, Ronald (May 1999). "Astronomiæ instauratæ mechanica by Tycho Brahe: Introduction". Special Collections Department. Smithsonian Institution Libraries . Retrieved July 11, 2020. The armillary sphere was reintroduced in the national arms and in the national Flag of Portugal in 1911.

Armillary sphere rings like the ones in the British Museum’s collection and the Swedish Historical Museum (top) serve a more benign purpose. Folded together, the two-part outer hoop and three interior hoops give the illusion of a simple gold band. Slipped off the wearer’s finger, they can fan out into a physical model of celestial longitude and latitude. Colure is one of two principal meridians (great circles) on the celestial sphere—equinoctial colure and solstitial colure.a b Savage-Smith, Emilie (2017). "Of Making Celestial Globes There Seems No End" (PDF). Bulletin of the Scientific Instrument Society. No. 132: 1–9.

Lindberg, David C.; Shank, Michael H. (7 October 2013). The Cambridge History of Science: Volume 2, Medieval Science. Cambridge University Press. p.173. ISBN 978-1-316-02547-5 . Retrieved 15 May 2018.

Spheres and globes

The ecliptic B, which is divided into 12 signs, and each sign into 30 degrees, and also into the months and days of the year; in such a manner, that the degree or point of the ecliptic in which the sun is, on any given day, stands over that day in the circle of months. For most of the second half of the 20th century this object was described by the Whipple Museum as having been made in about 1450. This would make it one of the earliest surviving demonstrational armillaries. Two other armillary spheres held in other museums date from this period, however this object is rather different from both of these. It is very difficult to date the armillary using the style of the lettering. The letter-shapes used to label the rings of the sphere suggest that it may have been produced at an even earlier date: perhaps in the 14th century.