Card-Mica covered with paper, blue with blue and black markings, graduated to 1/4 points and quadrantally in degrees.
Needle- Four very light edge bar needles, composed of one very thin strip of steel, 2 x 7" and 2 x 5" long, and 0.5" deep. Mounted 1.9" apart. All attached to a light metal ring which is screwed to card.
Pivot- Cone-shaped brass pivot cap with white metal bearing 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 in N-S direction, these carrying sliding weights.