Parts only - base and frame for a Sprengnether Long-Period Horizontal Seismometer, once part of the WWSSN. Missing pendulum and associated coils and mass. Pick-up only, but will crate for shipping, buyer makes shipping arrangements. (loading dock serviceable)
https://www.si.edu/object/long-period-horizontal-seismometer-wwssn%3Anmah_1445876