Title supplied by cataloger based on information from sheet label. Image is a photoreduction of the mosaic created from original aerial photographs. Designating symbol DB. Form of individual image numbering: DB-1G-[number], DB-2G-[number], DB-3G-[number], or DB-4G-[number]."Flying completed 9-1-50" Flown by Aero Service Corp. Philidelphia, 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/