Flights flown between July 27, 1938 and August 1, 1939 by Iowa Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BGW-1-3 through BGW-1-196. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Massac County (Ill.) (W 88°56′--W 88°29′/N 37°20′--N 37°04′)
Illinois State Geological Survey
78 remote-sensing images, .53 gigabytes, average file 7.02 megabytes
Scanned from 9 x 9 contact prints (nominal scale ca. 1:20,000) on Crosfield Celsis 6200 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 6:1. Uncompressed TIFF images on cd available from the Illinois State Library Map Dept.