Flights flown between August 13, 1938 and December 15, 1938 by Iowa Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BGK-1-2 through BGK-5-37. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Effingham County (Ill.) (W 88°48′--W 88°22′/N 39°13′--N38°55′)
Illinois State Geological Survey
248 remote-sensing images, 1.40 gigabytes, average file 5.78 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.