"From Maxwell's field equations only the well-known (transverse) Hertzian waves can be derived, whereas the calculation of longitudinal electromagnetic waves gives zero as a result. This is a flaw of the field theory, since longitudinal waves exist for all particle waves, like e.g. as plasma wave, as photon- or neutrino radiation."
I also found this on the internet. It's from an article called ' Faster Than Light, and it's written by a guy called Hugo Gernsback - "...Dr. Tesla revealed that he had made a number of surprising discoveries in the high-frequency electric field and that, in the course of these experiments, he had become convinced that he propagated frequencies at speeds higher than the speed of light.
In his patent No. 787,412, filed May 16, 1900, Tesla showed that the current of his transmitter passed over the earth's surface with a speed of 292,830 miles per second, while radio waves proceed with the velocity of light Tesla holds, however, that our present "radio" waves are not true Hertzian waves, but really sound waves."
"Although Tesla took those first steps toward radio, he did not benefit from its financial returns because his visions were in other directions. The equipment he constructed and patented were oriented toward a complete planetary communications system. First, he built a large experimental facility near Colorado Springs, Colorado, where he explored natural electromagnetic signals, especially from lightning. He then went on to transmit high power and large potential electromagnetic signals around the earth, while utilizing varying versions of what has become known as 'Tesla coils'.
Tesla considered his methods of transmission not 'Hertzian waves', or what we now refer to as transverse electromagnetic waves (radio), but another type of signal transmission. He described them as faster-than-light (FTL) longitudinal wave transmissions." - I would be sure to read this entire page because it's very interesting.
Tesla had some ideas about broadcasting electricity where "...the air will serve as a conductor for the current produced, and the latter will be transmitted through the air with, it may be, even less resistance than through an ordinary copper wire."
"....he speaks of tuning his apparatus until Hertzian radiations have been eliminated, he is referring to using ELF vibrations: "...the Hertzian effect has gradually been reduced through the lowering of frequency"."