Semicircular Military Protractor Small 320×164 Medium 640×327 Large 1024×524 Download Tiff Original 2400×1228 | (252.9 KB) Description The semicircular protractor used to measure angles by the military. Keywords angle reading, military protractor, semicircular protractor Galleries Protractors Source: Chief of Engineers Advance Map and Aerial Photograph Reading (Washington, DC: United States Government Printing Office, 1941)
