Seismographs
Seismographs are used all over the world to record and measure seismic waves. Seismograms are attached to the ground and is the paper that records the earthquake movement. The seismographs also have a pole and at the end of the pole there is a wire. On the wooden srpport sticking out horizontal to the ground there is a bar holding the wire. At the very end of the wire there is a weight. Attached to the weight there is a tiny pen recording the seismic waves on the seismogram. On a seismograph, there is a rotating drum that moves around for twenty four hours and has paper on it that gets the recordings and measurements of seismic waves. All this was made and developed by John Milne in 1893. His devolopment, the siesmographs, are relativly unchanged to this day. Before the development of the Richter Scale, the scientists would have to assign a number to earthquake based on the visible damage that the earthquake made. They are very useful because they can determine what size the earthquake was and sometime where it was.