This instrument was designed to measure the tidal strains of the earth produced by the gravitational action of the sun and moon. It also could record ultra-long seismic waves and the possible free oscillation of the earth. This photo is probably taken at an installation in Santiago, Chile. See Engineering & Science, October 1957.
Demonstration in handling and transporting of Kew-type mercurial barometer. Photograph from the portfolio compiled to acquaint fully “the Army Air Corps, the Navy and the Weather Bureau with the curriculum offered to students in Government sponsored courses at the California Institute of Technology.” (Historical File A12.4)