Seismograph

sismo-graf, an instrument designed to record an earthquake shock. The simplest contrivance is a cup of molasses. The wave of molasses raised by the quake registers itself by a stain on the side of the cup. The scientific instrument, known also as seismometer (sis), registers by means of three delicate pointers tracing lines on smoked glass. A tremor of the earth starts clockwork that sets the panes of glass in motion. One of these pointers points in a vertical direction, the others are horizontal. The direction, violence, and duration of the motion is indicated by lines traced on the glass. An ingenious contrivance causes a clock to stop at the beginning of the tremor, thus fixing the time of occurrence. The Japanese excel in the study of earthquakes by means of these instruments.