pl23_theb1791.jpg
![Using dynamite to excavate a bench mark hole theb1791.jpg Using dynamite to excavate a bench mark hole](https://s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_theb1791.jpg)
Description
Using dynamite to excavate a bench mark hole.Note dirt flying out of hole.Level party of H. J. Oliver
Credit
C&GS; Special Report Oliver 1932
Display Date
1932
Location
Northern California
Collection
Historic Coast & Geodetic Survey
Geodesy
Determining the Elevations - Leveling a Continent
Keywords
Geodesy
Leveling