Triple Wave Propagation
There is no such thing as a simple wave form such as are illustrated on page 11. These drawings are simple representations that are easy to deal with. The real method and manner of wave form configuration is much more complex. The first drawing on page 10 illustrates that each wave has inherent within itself three modes of vibration each of which propagate or travel at right angles to each other. A longitudinal wave travels back and forth away from its source. This is a straight line motion. A Transverse or Shear wave travels from left to right of this longitudinal wave. This second mode is a zig-zag motion. The third wave called either a Raleigh or Lamb wave is again set at 90¡ to the Shear or Transverse wave. The third mode is a circular or spiralling motion. This last wave is usually found to travel along a surface such as on water but not generally through the water as the other two modes prefer to do.
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