Flights flown between July 2, 1939 and July 29, 1939 by Midwest Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BXH-1-3 through BXH-4-128. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Stephenson County (Ill.) / W0895500-W0892400 / N0423000-N0421200
Illinois State Geological Survey
209 remote-sensing images, 1.17 gigabytes, average file 5.73 megabytes
Scanned from 7 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.