Bowl-Copper, fitted with a stop mechanism consisting of a card lifter operated from the bottom of the bowl. Lubber line engraved on ivory plate attached to inside of bowl. Base weighted with lead. roughly cut glass, lossely laid on top. Fitted with brass hoop and mounted in brass gimbals.
Card-Mica with thin paper rim graduated to 1/2 points and in 360 degs. Reverse of card has wax balancing blob. Dia. 6.25" (15.9cm).
Needle-Elongated hollow diamond, 6.25" (15.9cm) long.
Pivot-Steel pin mounted on pillar secured to base of bowl. Card lifter operates by a sleeve around the pillar.
Azimuth sights-Two sight vanes fixed to rim of bowl. Rear sight, 6" (15.2cm), fitted with sighting thread. Other vane with a narrow slit, 4" (10.1cm).
Mounted on stand which has access hole in base, covered by brass plate. 10.25" (26.1cm) square.