Francis X. Popper taking sight with alidade.
Plane table work on the Sacramento River Delta
Image ID: theb1748, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: Sacramento River Delta, California
Photo Date: January 9, 1941
Credit: Captain Francis X. Popper, C&GS
Category: Topography/Plane Table/
• High Resolution Photo Available