Circular-hinged sector. Early English type sector; lines are duplicates of those described by Gunter (1624). Friction leaf (.1x17.7x2.5 cm). Single scale on outside edge of one leg is numbered 0-70 right to left and then 80-140 left to right using the same marks. Single scale on outside edge of other leg is numbered 0-9 right to left, then 9-18 left to right (and upside down) using the same marks.
