US (Army) 30" Straight Edge Scale antique vintage old drafting tool Bowen MD USN

Description

You are buying ONE (1) 30" polished steel sharp sided straight edge and scale marked "US" and
Manufactured by
Bowen and Company
Bethesda, Maryland U.S.A.
Clearly made for the US government and probably for the Department of the Army.
Condition of the edges is PERFECT.
I do not understand the scale markings but there are probably mfg. errors in the scale markings from overstamping differing numbers on top of each other.. I am not sure that the numbers are useful but the scale ticks are perfect.