Ptolemaic Armillary Sphere
A reproduction of a rare mid - 18th Century brass Ptolemaic armillary sphere, after Daniel Heckinger III, Augsburg (1735). The foot is composed of four scrolled brackets that straddle a windrose below and support a disc above. The wind rose is cut with sixteen triangular points each labelled with the appropriate wind: e.g., NORD, OST, SUD, WEST. At the centre is a pin-bearing with a magnetic compass with cover and needle. The edge is divided into degrees 0 - 90 in four quadrants, and the magnetic declination is marked by an arrow at 18º West of North because this is the value applied between 1730 and 1750 in Augsburg (Wagner, 1997).
From the disc rises a baluster stem with a fluted cap, holding two crossed semicircles that support the armillary sphere. The horizon ring is divided into the calendar and zodiac. Each division of the zodiac has the name and symbol representation.
The Armillary Sphere is made from strips of brass, with a meridian ring which is divided on one side into degrees, with half of the ring labelled from 90-0-90, the other from 0-90-0. At the top is a 24-hour circle with a pointer. The rings are labelled and the ecliptic band is divided in divisions of the zodiac, with names and symbols. A small Earth ball 9/16 in diameter (23mm) has an equatorial band, and an ecliptic band and turns on a central rod.
The overall height is 16 ¾ in ( 425mm); radius of horizontal ring 9 7/8 in (250mm) Signed Dean R. White fecit Bampton Devonia (and dated)
Wagner, Gerhard G. Sonnenuhren und wissenschaftliche Instrumente (Wurzburg: Mainfrankisches Museum, 1997) p.55.