Card- Cardboard, white with black markings, graduated to 32 points. A rim of paper 0.75" wide is stuck at the outer edge of card and this is graduated quadrantally in degrees. The inner prtion of card can be rotated independently of the outer rim, thus enabling an adjustment to be made allowing for variation.
Pivot- Crude cone-shaped brass pivot cap, no jewel, screwed through centre of needle.
Needle- Single flat bar type 6.2"long, 0.6" wide at centre and waisted to 0.25" at mid-length and expanding at ends to 0.6".