Savage-Smith, Emilie (1985), Islamicate Celestial Globes: Their History, Construction, and Use, Smithsonian Institution Press, Washington, D.C.

The solstitial colure H, passing through the poles of the heaven, and through the solstitial points Cancer and Capricorn, in the ecliptic. Each quarter of the former of these colures is divided into 90 degrees, from the equinoctial to the poles of the world, for showing the declination of the sun, moon, and stars; and each quarter of the latter, from the ecliptic as e and f, to its poles b and d, for showing the latitude of the stars. 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.Enter the fictional world of James Bond, and you’ll find a number of handy dandy spy rings including one that doubles as a camera, and another capable of shattering bulletproof glass with a single twist. The Arctic Circle E, and the Antarctic Circle F, each 23 1⁄ 2 degrees from its respective pole at N and S. This example was probably made as a decorative item of furniture for a Library as the engraved brass circles have no practical service for scientific purposes. Christopher Cullen, "Joseph Needham on Chinese Astronomy", Past and Present, No. 87 (May, 1980), pp. 39–53 (45)

In its simplest form, consisting of a ring fixed in the plane of the equator, the armilla is one of the most ancient of astronomical instruments. Slightly developed, it was crossed by another ring fixed in the plane of the meridian. The first was an equinoctial, the second a solstitial armilla. Shadows were used as indices of the sun's positions, in combinations with angular divisions. When several rings or circles were combined representing the great circles of the heavens, the instrument became an armillary sphere. [1] 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. The flag of Portugal features an armillary sphere. The armillary sphere is also featured in Portuguese heraldry, associated with the Portuguese discoveries during the Age of Exploration. 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. In the flag of the Empire of Brazil, the armillary sphere is also featured.

Forthcoming events

Antarctic Circle: This small circle forms the southernmost latitude on earth at which the center of the sun’s disk travels completely around the horizon for a full 24 hours on the December solstice (summer solstice in the Southern hemisphere). Currently the latitude of the Antarctic Circleis 66 o 33.8’ S. The latitude of the Antarctic Circlevaries from67.9 o S and 65.5 o Sover about 41,000 years. The Antarctic Circleis moving north toward the equator at about 50 feet per year. The tropic of Cancer C, touching the ecliptic at the beginning of Cancer in e, and the tropic of Capricorn D, touching the ecliptic at the beginning of Capricorn in f; each 23 1⁄ 2 degrees from the equinoctial circle. At the centre of the sphere is the Earth. As the Earth is stationary in this model, it is the celestial sphere which rotates about it and acts as a reference system for locating the celestial bodies – stars, in particular – from a geocentric perspective. The sphere is mounted at the celestial poles that define the axis of rotation, and its structure includes an equatorial ring and, parallel to this, two smaller rings representing the Tropics of Cancer and Capricorn to the north and south, respectively.