The Seismic Down-Hole method is part (with the Cross-Hole) of the borehole seismic surveys. The main difference between them is the location of the geophones and the seismic source. In the Down-Hole technique the seismic source is on the surface, and a three-component borehole geophone is placed inside the borehole at different depths. At the surface, close to the borehole P- and S-waves are excited hitting a plate, a wooden beam or a steel beam. The geophone is lowered (or raised) at given intervals. As a result, the seismic waves velocities (Vp and Vs) can be obtained.