*In free space the velocity of electromagnetic waves is close to 1 ft/ns; in limestone the velocity drops to about 0.3 ft/ns; and, in coaxial cable, to 0.66 ft/ns. In the case of signals carried into the chambers by the receiving coaxial cables, the observed velocity of propagation corresponds to propagation down the outer shield of the coaxial cable, so that the outer shield acts as a wire exciting a waveguide below cutoff. The same phenomenon is frequently used to advantage in highway engineering--long wires strung through highway tunnels fill the tunnels with local broadcast transmissions, preventing loss of radio signals in automobiles traveling in the tunnels. The passageways of the pyramids and/or most highway tunnels are small enough at the radio wavelengths to act as waveguides below cutoff; thus, radiation traveling down the passageway or tunnel is enormously attenuated in very short distances, yet a long wire through such a tunnel can effectively fill the tunnel with RF energy.