Related Object Info
Cox & Stevens/United States Army Air Forces rolling ruler
Brass base with trapezoidal cross-section, into which are inserted two knurled brass wheels, one near each end. To the outside of each of the wheels are two L-shaped brass plates, bolted to the base at one end and bolted to one another at the other. Between the two wheels is a raised brass rectangle.
Printed along the top and bottom edges of the rule is a scale carrying values from 0 to 90. Below the left end of each scale is printed: "MAP SCALE / 1=500,000".
