Testing airplanes lenses used in map making. Washington, D.C., May 6. Dr. F.E. Washer of the U.S. Bureau of Standards testing the lens for the airplane cameras that are used by the Army and Navy. There are lights in the rear of the columnmeters and exposures are made on the photographic plate in front of the doctor. The lens are tested for distortion, focal length, and definition. This work must be very exacting as a small error would make an error of many miles on the maps made by the aerial cameras, 5/6/1937