Spring

Most of the water in the mine comes from this spring.

This is also where the GWR superconducting gravimeter was situated during its temporary deployement at BFO in 1994.

Technician Heinz Otto mounting the Askania pendulum to the wall of the vault. Note the solid granite.

$\======$ $\======$ Schematic cross-section of askania pendulum (Agnew, Reviews of Geophysics, 1986) $\======$ $\======$