L7790

Armillary sphere Long Caption: The whole sphere moves from half way down the base column and the horizon ring is engraved with names of the eight winds, months and zodiac names and divisions. The primary sphere consists of eight brass rings and in the centre there are two movable systems of brass rings connected to two short axes fixed at the North and South ecliptic poles of the primary sphere. These systems represent the orbs of the Sun and the Moon. The larger system, for the Sun, consists of two brass rings, which are fixed perpendicularly to each other. Both these rings, one of which carries a disc for the Sun, represent circles of latitude. The smaller system, for the Moon, also consists of two brass rings, similarly constructed, with one of them carrying a symbol for the Moon. In the centre, there is a small 'gold'-painted sphere, presumably made of papier mache, mounted on an equatorial polar axis connected to two little arcs. These arcs are attached to the two ecliptic axes, so that the poles of this sphere always point to the North and South equatorial poles of the primary sphere. The sphere in the centre is probably a later replacement, in a vain attempt to turn this fundamentally geocentric armillary sphere into a heliocentric one. Credit line: © National Maritime Museum, Greenwich, London. Object: AST0634 Artist: Joannes Paolo Ferreri Date: 1624 Medium: brass Size: Overall: 864 mm x 513 mm Click here to buy a bespoke print of this image.