Flights flown between June 29, 1939 and September 9, 1939 by Midwest Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BXI BXC-1-16 through BXC-3-165. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Mason County (Ill.) (W 90°21′--W 89°36′/N 40°27′--N 40°03′)
Illinois State Geological Survey
319 remote-sensing images, 1.09 gigabytes, average file 3.5 megabytes
Scanned from 9 x 9 contact prints (nominal scale ca. 1:20,000) on Crosfield 646IE drum scanning system at 750 dpi. Quality assurance target not published but available by contacting the Illinois State Library Map Dept. MrSID files compressed at a target ratio of 12:1. Uncompressed TIFF images on cd available from the Illinois State Library Map Dept.