Description
Whipple purchased this modest-looking armillary for a small sum in a London antique shop in 1928. We now think it is the oldest surviving instrument of its kind in the world.
03/01/2024
Created by: Morgan Bell on 03/01/2024

Description
An armillary sphere is a model of the universe. The name comes from the Latin armillae, meaning ‘rings’, and refers to the ‘great circles’ used for plotting astronomical co-ordinates on the ‘celestial sphere’ that surrounds the earth. The rings are: the Equator, Tropics, Arctic Circles, and the Ecliptic (the apparent motion of the Sun over the course of the year). The wooden ball in the centre represents the Earth.

Armillary spheres have been made since antiquity. They were first constructed as observational tools, then in the mediaeval period as tools for teaching the principles of Ptolemaic, Earth-centred astronomy. Very few examples of these instruments survive from earlier than the 16th century – perhaps due to their fragility, which makes them more difficult to preserve than a flat object such as an astrolabe.

Armillary spheres are astronomical instruments that modelled the motions of the celestial sphere, and were used primarily for teaching or didactic purposes. These observational devices were known in the Islamic world and was introduced to the Europe through this culture. During the medieval period, astronomy was a central part of medical learning. This particular example is crude in its engraving, and it appears that the stand was produced at a later date. The model shows ten celestial features: the primum mobile, the Arctic circle, the solstitial colure, the equinoctial colure, the tropic of Cancer, the equinoctial or Equator, the tropic of Capricorn, the Antarctic circle, the right horizon and the oblique horizon. The shape of the engraved lettering corresponds to round Gothic or Lombardic, which replaced Western Latin inscriptions beginning in the twelfth century and continued to shape the form of letters until the fifteenth century.

From display label:

Armillary spheres have been made since antiquity. They were first constructed as observational tools, then in the mediaeval period as models of the of Ptolemaic, Earth- centred universe.
The name comes from the Latin armillae, which means ‘rings’. The rings represent the ‘great circles’ that are used for plotting astronomical coordinates. These are: the equator, tropics, arctic circles, and the ecliptic (the apparent motion of the Sun over the course of the year). The wooden ball in the centre represents the Earth.

03/06/2014
Created by: Allison Ksiazkiewicz on 03/06/2014