Card-Mica covered with paper, blue with blue and black markings, graduated to 1/4 points and quadrantally in degrees. At centre of card is a hole 3" in dia.
Needle- Four light edge bar needles, composed of one thin strip of steel, 2 x 7.25" and 2 x 5.25" long, and 0.6" deep. The upper edges of the needles are slightly rounded in concave fashion which reduces their depth to 0.25" at centre. All attached to a light metal ring which is screwed to card.
Pivot- Cone-shaped brass pivot cap with jewel at top, screwed through centre of light framework which has two short arms secured to the two inner needles and two long arms attached to the metal ring of card.