ASTRAGAL, ASTRAGALUS, in Anatomy, a Bone of the Heel, having a convex Head, articulated with the two Facils of the Leg, by Ginglymus. See LEG and FOOT.
The Astragalus called Talus, and Os Calcis, is the first Bone of the Tarsus. See TALUS and TARSUS.
Some also apply the Name to the Vertebrae of the Neck.—Homer, in his Odyssey, uses the Term on this Occasion. See VERTEBRAE.
ASTRAGAL, in Architecture, is a little round Member, in form of a Ring, or Bracelet; serving as an Ornament on the Tops and at the Bottoms of Columns. See MOULDING, COLUMN, etc.: The Astragal is sometimes also used to separate the Fasciae of the Architrave; in which case it is wrought in Chaplets, or Beads and Berries, It is also used both above and below the Lists, adjoining immediately to the Squares or Die of the Pedestal. See DYE and PEDESTAL. The Word is derived from the Greek ἀστράγαλος, which signifies the ankle or Ankle-Bone.
ASTRAGAL, in Gunnery, is a Kind of Ring or Moulding on a piece of Ordnance, at about half a Foot’s Distance from the Mouth; serving as an Ornament to the Piece, as the former does to a Column. See ORDNANCE, CANNON, etc.
