Name/Title
S02.08.004Description
Donald R. Camburn is standing at a vacuum frame in the photography laboratory. He is placing a negative on top of a sheet of scribecoat. Geologic contact lines were originally hand drawn by the geologist to depict the geology being mapped. Cartographers in the Publications Section would make a negative of the hand drawn lines in the photography laboratory. The negative would be placed over the scribecoat and exposed, or burned, on the vacuum frame. Once placed in the vacuum frame with the glass top lowered and locked, the air would be vacuumed out producing a tight contact between the negative and the scribecoat. The vacuum frame could be tilted to a vertical position for a stronger exposure using an arc light. This would transfer the lines from the negative to the scribecoat. Scribecoat is a clear carrier sheet with a coating of semi-soft plastic on top. A chemical was painted onto the scribecoat before the burn. When the scribecoat was washed with water afterwards, the image of the scribed lines remained. Don was a cartographer in the Publications Section of the Ohio Geological Survey. The Ohio Department of Natural Resources, Division of Geological Survey's main office was located at 1207 Grandview Avenue, Grandview Heights, Ohio 43212 from 1962 through May 1973. The Image was taken in 1971.
This slide image included in the USGS National Digital Catalog for NGGDPP Grant G15AP00115 in FY2015.Context
Man holding blackout maps at pressing machine. Taken at the office in Grandview Heights, Ohio.