The quadrant has two scales, the outer ('Quadrans altitudinis') 0 to 90, divided to 10, subdivided to 5 and to 1 with alternate hatching, numbered by 10; the inner ('Quadrans distantijs inseruiens') 0 to 90, similarly divided and numbered. The inner quadrant is used with the eye at the apex of the quadrant, the outer with the eye on the limb. An alidade pivoted at the apex, with slit and half-solid sights, is shaped to accommodate two similar sights fixed to one edge. A steel spring is attached to the reverse of the quadrant so that a quadrant arc on top restrains the alidade and holds it at its reading. A calendar scale on the reverse is marked: 'Tabula generalis ad inueniendu diem paschatis et intercallum Iuxts Kalendarii reformatione'.
Shaped wooden box, covered and lined with leather, top missing.
