Bowl-Brass, fitted with a glass bottom and has a heavy balancing ring inside bowl. Has a mica covered aperture cut in side to illuminate the card. Inside of bowl painted white. Four lubber lines are deeply scribed into side of bowl. The verge glass has corresponding lubber lines scribed on the underside of glass in form of a cross. A card lifter is fitted which raises card from swivel cap when necessary. Verge ring is graduated to 360 degress, and a brass spigot to accommodate an aximuth sight is mounted at centre of glass. Mounted in a black painted brass gimbal ring 11.25" (28.5cm) in a wooden box 13 x 13 x 9.25" (33 x 33 x 23.5cm), one side of which has a socket for a lamp. A curved metal plate slopes upwards from the lower edge of lamp aperture; this, and interior of box painted white to reflect light through bottom and side of bowl to the card. Two carrying handles and two arms to lock gimbals are fitted in box. Seven 1" spare needles are contained in a recess in box lid.
Card- dia.8" (20.3cm) mica covered with paper, white with black markings, graduated to 1/2 points and quadrantally in degrees. North point marked by a star, and a crown & anchor device. the centre of card has a hole 1.25" (3.2cm) in dia. to accommodate pivot mount. On underside of card at E & W points are two brass weights.
Needle- flat bar type 8"(20.3cm) long with expanded centre to which is attached a brass ring 7" (17.8cm) in dia.; the ring is attached at the ends of the needle and at the E & W points of the card. The brass pivot cup is carried at centre of bridge mounted across centre of expanded needle.
Pivot- Brass pivot stem secured to glass bottom of bowl, to the top of which is screwed a steel pivot point. the card lifter mechanism is mounted on the stem.