Second of two maps of San Francisco and the Bay Area, made by the US Coast Survey in 1918 and 1919, found in a garage in San Francisco. Thanks to Ann Murphy for sharing these map images.
“Geodesy, is the Earth science of accurately measuring and understanding Earth's geometric shape, orientation in space, and gravitational field. The field also incorporates studies of how these properties change over time and equivalent measurements for other planets.” wikipedia.com
