Title supplied by cataloger based on information from sheet label. Image is a photoreduction of the mosaic created from original aerial photographs. Designating symbol BZS. Form of individual image numbering: BZS-1-[number], BZS-2-[number], or BZS-3-[number]."Flown by Aero Service Corp. Philidelphia, Pa.""Date of completion Aug. 3, 1939.""Approximate scale, 1:20,000" [refers to individual images from which mosaic was made].
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