H. Winfield Secor, Nikola Tesla Maps Our Electrical Future, Science and Invention, 19(12), p. 1077, 1124-1126. Quote: "Nikola Tesla upholds the startling theory formulated by him long ago, that the radio transmitters as now used, do not emit Hertz waves, as commonly believed, but waves of sound... He says that a Hertz wave would only be possible in a solid ether, but he has demonstrated (as has Keely) already in 1897 that the ether is a gas, which can only transmit waves of sound; that is such as are propagated by alternate compressions and rarefactions of the medium in which transverse waves are absolutely impossible."

A more thorough discussion of practical use of electricity as longitudinal waves see:
James Bowman Lindsay's lecture, 1799-1862.

In Tom Bearden’s glossary under the 'Tesla, Nikola' heading... one recognizes Tesla’s genius regarding his ‘understanding’ that….. "From his experiments he knew that the EM wave in vacuum was longitudinal, like sound waves……. I showed that the universal medium is a gaseous body in which only longitudinal pulses can be propagated, involving alternating compressions and expansions similar to those produced by sound waves in the air. Thus, a wireless transmitter does not emit Hertz waves which are a myth, but sound waves in the ether, behaving in every respect like those in the air, except that, owing to the great elastic force and extremely small density of the medium, their speed is that of light." Nikola Tesla
TESLA, NIKOLA

See Also

3.8 - There are no Waves
3.9 - Nodes Travel Faster Than Waves or Light
8.3 - Conventional View of Wave Motion
8.4 - Wave types and metaphors
8.5 - Wave Motion Observables
8.6 - Wave Form Components
8.8 - Water Wave Model
9.2 - Wave Velocity Propagation Questions
9.30 - Eighteen Attributes of a Wave
9.31 - Oscillatory Motion creating Waveforms
9.34 - Wave Propagation
9.35 - Wave Flow
12.05 - Three Main Parts of a Wave
16.06 - Electric Waves are Sound Waves
Compression Wave
Compression Wave Velocity
Curved Wave Universe of Motion
Dissociating Water with Microwave
Figure 6.9 - Russell depicts his waves in two ways
Figure 6.10 - Wave Dynamics between Cube Corners
Figure 7.1 - Step 1 - Wave Vortex Crests at Maximum Polarization
Figure 8.1 - Russells Painting of Wave Form Dynamics
Figure 8.10 - Each Phase of a Wave as Discrete Steps
Figure 8.11 - Four Fundamental Phases of a Wave
Figure 8.14 - Some Basic Waveforms and their constituent Aliquot Parts
Figure 8.2 - Compression Wave Phase Illustration
Figure 8.3 - Coiled Spring showing Longitudinal Wave
Figure 8.4 - Transverse Wave
Figure 9.10 - Phases of a Wave as series of Expansions and Contractions
Figure 9.11 - Compression Wave with expanded and contracted Orbits
Figure 9.13 - Wave Flow as function of Periodic Attraction and Dispersion
Figure 9.14 - Wave Flow and Phase as function of Particle Rotation
Figure 9.15 - Wave Flow and Wave Length as function of Particle Oscillatory Rotation
Figure 9.5 - Phases of a Wave as series of Expansions and Contractions
Figure 9.9 - Wave Disturbance from 0 Center to 0 Center
Figure 12.10 - Russells Locked Potential Wave
Figure 12.12 - Russells Multiple Octave Waves as Fibonacci Spirals
Figure 13.13 - Gravity Syntropic and Radiative Entropic Waves
Figure 14.07 - Love Principle: Two sympathetic waves expanding from two points have one coincident centering locus
In the Wave lies the Secret of Creation
Laws of Vibration
Longitudinal Wave
Longitudinal Waves in Vacuum
Matter Waves and Electricity
Nodal Waves
One More Step Toward Building The Cube-Sphere Wave-Field
Quantum Entanglement
Rayleigh Wave
Shock Wave
Sympathetic Oscillation
Sympathetic Vibration
Table 12.02.01 - Wavelengths and Frequencies
Three Main Parts of a Wave
Transverse Wave
wave
Wave Field
Wave Fields - Summarize and Simplify
wave number
WaveLength