Center Finding Rulers

Calibrations are on two edges, on one side. This rule is designed as an efficient aid in finding the center between two points; a significant, time-saving device
in pattern-making, tailoring, forms design and crafts of all kind.

There is a zero-point at the center of the top edge of the ruler, with equal incremental measurements to the left and to the right, in 32nds of an inch. The bottom edge is a standard ruler calibrated in 16ths.