The new, improved design of seismograph model gives students a better understanding of how earthquakes are measured and calculated to intensity. It is actually a pen attached to a weight suspended from a support. Vibrate the table on which the model is mounted; the support moves with vibrations of the table, but the pen remains stationary. Vibrations are recorded on a roll of paper as it is pulled through the frame. Use one model for classroom demonstrations, or several for comparison exercises. It includes a Teacher’s guide with lessons. Size: 12″L x 6″W x 5″H.