In the wooded hillside of Hainberg, near Göttingen, Germany, stands an old seismological station. The Wiechert Earthquake Station was built in 1902 by the noted German physicist and geophysicist, Emil Wiechert, to carry out research in the emerging field of geophysics. Wiechert built several seismographs there to record tremors. These instruments have been recording data uninterruptedly since then, becoming the world’s oldest, still functioning seismograph.

Emil Wiechert was interested in learning about the structure of the earth. A few years prior, he had published the first verifiable model of the Earth's interior as a series of shells. He argued that since the density of the Earth's surface rocks was different from the mean density of the Earth, the earth must be made of different layers of rocks of different densities. He concluded, correctly, that the earth has a heavy iron core.

The Mintrop ball readying for a drop.