Bowl-Brass, black painted lubber line. Weighted at base. Boss in centre of verge glass which serves the double purpose of retaining the card on the pivot and providing a socket for a shadow pin.
Card-Dia. 6" (15.2cm) "Kelvin light dry type". White with black markings, graduated quadrantally in degrees and to 1/4 points. Paper rim attached to centre ring, into which jewelled pivot cap fits, by radiating threads.
Needle-Four parallel needles suspended belwo card.
Pivot-Pivot point in brass stem mounted at base of bowl.