The dial has a round brass box containing a compass with its lid, on top of which is a nocturnal. The folding hour ring is marked with common hours from IIII to XII to VIII and is set for latitude by placing the pointed arm, opposite the gnomon, in the appropriate depression in the cross-bar of the compass cover. The compass has engraved the cardinal points 'Septe', 'oriet', 'midi', 'occi' in Gothic script. On the bottom of the instrument is a coat-of-arms with a rampant lion, probably of an abbot or bishop.
