Flights flown between October 24, 1938 and June 5, 1939 by Iowa Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BHE-1-21 through BHE-4-90. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Shelby County (Ill.) / W0890800-W0882800 / N0393900-N0391300
Illinois State Geological Survey
403 remote-sensing images, 2.52 gigabytes, average file 6.40 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 12:1. Uncompressed TIFF images on cd available from the Illinois State Library Map Dept.
Mode of access: World Wide Web. System requirements: Plug-in or image viewer, ExpressView Browser plug-in available for download. System requirements for interactive map: Google Chrome best.