Signedbase of rule, top center: COX & STEVENS AIRCRAFT CORP.–#498 ;
on raised bar in center of base, center: PROPERTY – AIR FORCE / UNITED STATES ARMY
Inscribedbase of rule, bottom center: INTERCEPT OFFICERS EQUIPMENT
FunctionUsed for measuring and drafting on maps with a 1:500,000 scale. By sliding the ruler on its wheels, the user can draw parallel lines any distance apart. This ruler was specifically designed for use in air navigation by the United States Army Air Forces.
ProvenancePrivate Donor, Troy, New York.