Lehman Seismometer in Classroom
The 18-second period Lehman horizontal seismometer is located in rear of the Earth Science classroom.
The home-made Plexiglas case keeps air currents from
affecting the seismometer boom.
This seismometer is located on a metal table because experience with a prior wooden table indicated that the wood varied too much with the changes in relative humidity as the building cycled between the cooling and heating seasons.