Boris Galitzin and his electromagnetic seismograph.
Galitzin, an inventor and prince in the Russian Empire, was the first to develop a seismometer based on electromagnetic induction around 1906. A signal is generated from a mass wrapped in a coil of wire, surrounded by a fixed magnet. As the Earth moves, the mass moves in the magnet's magnetic field produced by the magnet, and a voltage is produced in the coil of wire that can be measured and recorded. As a bonus, the induced current in the coil produces a secondary magnetic field that damps the motion of the mass in a predictable and useful way. Up until this time, seismometer mass motions were mechanically or optically transferred to a recording system. Galitzin's electromagnetic design became the basis for seismic instrumentation used through much of the past 100 years.

This rare photograph of Galitzin was brought back to Colorado School of Mines Geophysics Professor Tom Boyd by a friend who discovered it during a visit to Russia several years ago.