Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol BKS. Form of individual image numbering: BKS-1HF-[number], BKS-2H-[number], BKS-3H-[number], or BKS-4H-[number]."Flying completed 10-9-51" Flown by Penna. Aerial Surveys, Inc. New Cumberland, PA."Approximate scale, 1:20,000" [refers to individual images from which mosaic was made]. Contact the Map Collection at The University of Iowa Libraries: http://www.lib.uiowa.edu/maps/contact/