Wardenclyffe Tower

For the Allan Holdsworth album, see Wardenclyffe Tower (album).

1904 image of Wardenclyffe Tower located in Shoreham, Long Island, New York. The 94 by 94 ft (29 m) brick building was designed by architect Stanford White.

Wardenclyffe Tower (1901–1917) also known as the Tesla Tower, was an early wireless transmission tower designed by Nikola Tesla and intended for commercial trans-Atlantic wireless telephony, broadcasting, and proof-of-concept demonstrations of wireless power transmission. It was never fully operational, and the tower was demolished in 1917.

The tower was named after James S. Warden, a western lawyer and banker who had purchased land for the endeavor in Shoreham, Long Island, about sixty miles from Manhattan. Here he built a resort community known as Wardenclyffe-On-Sound. Warden believed that with the implementation of Tesla's "world system" a "Radio City" would arise in the area. He offered Tesla 200 acres (81 ha) of land close to a railway line on which to build his wireless telecommunications tower and laboratory facility.

History

Construction

Tesla Ready for Business - August 7, 1901 New-York tribune article

Tesla's Wardenclyffe plant on Long Island in partial stage of completion. Work on the 55-foot-diameter (17 m) cupola had not yet begun. There is a coal car parked next to the building. From this facility, Tesla hoped to demonstrate wireless transmission of electrical energy across the Atlantic. Circa 1902.

Tesla began planning the Wardenclyffe Tower facility ca. 1898 and in 1901 construction began on the land near Long Island Sound. Architect Stanford White designed the Wardenclyffe facility main building. The tower was designed by W.D. Crow, an associate of White. Funding for Tesla's project was provided by influential industrialists and other venture capitalists. The project was initially backed by the wealthy J. P. Morgan who had invested $150,000 in the facility (more than $3 million in 2009 dollars).

In June 1902 Tesla moved his laboratory operations from his Houston Street laboratory to Wardenclyffe. However, in 1903, when the tower structure was near completion, it was still not yet functional due to last-minute design changes. Construction costs eventually exceeded the money provided by Morgan and additional financiers were reluctant to come forward (Tesla's other major financier was John Jacob Astor). By July 1904 Morgan (and the other investors) finally decided they would not provide any additional financing. In May 1905 Tesla's patents on alternating current motors and other methods of power transmission expired, halting royalty payments and causing a severe reduction of funding to the Wardenclyffe Tower. In an attempt to find alternative funding Tesla advertised the services of the Wardenclyffe facility but he was met with little success. By this time Tesla had also designed the Tesla turbine at Wardenclyffe and produced Tesla coils for sale to various businesses.

By 1905, since Tesla could not find any more backers, most of the site's activity had to be shut down. Employees were laid off in 1906, but parts of the building remained in use until 1907. In 1908, the property was foreclosed for the first time. Tesla procured a new mortgage from George C. Boldt, proprietor of the Waldorf-Astoria Hotel. The facility was partially abandoned around 1911, and the tower structure deteriorated. Between 1912 and 1915, Tesla's finances unraveled, and when the funders wanted to know how they were going to recapture their investments, Tesla was unable to give satisfactory answers. Newspaper headlines of the time labeled it "Tesla's million-dollar folly." The facility's main building was breached and vandalized around this time. Collapse of the Wardenclyffe project may have contributed to the mental breakdown Tesla experienced during this period. Coupled to the personal tragedy of Wardenclyffe was the 1895 fire at 35 South 5th Avenue, New York, in the building which housed Tesla's laboratory. In this fire, he lost much of his equipment, notes and documents. This produced in Tesla a state of severe depression.

Post-Tesla era

In 1915, legal ownership of the Wardenclyffe property was transferred to George Boldt of the Waldorf-Astoria Hotel for a $20,000 debt (about $400,000 in 2009 dollars). In July 4, 1917, during World War I, the tower was blown up with dynamite on orders of the United States Government which feared German spies were using it and that it could be used as a landmark for German submarines. Tesla was not in New York during the tower's destruction.

George Boldt wished to make the property available for sale. On April 20, 1922, Tesla lost an appeal of judgment versus his backers in the second foreclosure. This effectively locked Tesla out of any future development of the facility. In 1925, the property ownership was transferred to Walter L. Johnson of Brooklyn. On March 6, 1939, Plantacres, Inc. purchased the facility's land and subsequently leased it to Peerless Photo Products, Inc. AGFA Corporation bought the property from Peerless and is the current owner. The main building remains standing to this day. Agfa used the site from 1969 to 1992 then closed the facility. The site has undergone a final cleanup of waste produced during its Photo Products era. The clean up was conducted under the scrutiny of the New York State Department of Environmental Conservation, and paid for by AGFA. In 2009 they put the property up for sale for $1,650,000. Agfa has advertised that the land can “be delivered fully cleared and level.” It says it spent $5 million through September 2008 cleaning up silver and cadmium.

Preservation efforts

On February 14, 1967, the nonprofit public benefit corporation Brookhaven Town Historical Trust was established. It selected the Wardenclyffe facility to be designated as a historic site and as the first site to be preserved by the Trust on March 3, 1967. The Brookhaven Town Historic Trust was rescinded by resolution on February 1, 1972. There were never any appointments made after a legal opinion was received; it was never set up properly. On July 7, 1976, a plaque from Yugoslavia was installed by representatives from Brookhaven National Laboratory near the entrance of the building.  It reads:

Stanford White Building at the corner of Tesla Street and New York Route 25A in July 2009

IN THIS BUILDING
DESIGNED BY STANFORD WHITE, ARCHITECT
NIKOLA TESLA
BORN SMILJAN, YUGOSLAVIA 1856—DIED NEW YORK, U.S.A. 1943
CONSTRUCTED IN 1901–1905 WARDENCLYFFE
HUGE RADIO STATION WITH ANTENNA TOWER
187 FEET HIGH /DESTROYED 1917/, WHICH
WAS TO HAVE SERVED AS HIS FIRST WORLD
COMMUNICATIONS SYSTEM.
IN MEMORY OF 120TH ANNIVERSARY OF TESLA'S BIRTH
AND 200TH ANNIVERSARY OF THE INDEPENDENCE OF THE FIRST U.S.A

July 10, 1976

The sign was stolen from the property in November 2009. An anonymous benefactor is offering a $2000 reward if it is returned to the property.

Designation of the structure as a National Landmark is awaiting completion of plant decommissioning activities by its present owner.

In 1976, an application was filed to nominate the main building for listing on the National Register of Historic Places (NRHP). It failed to get approval. The Tesla Wardenclyffe Project, Inc. was established in 1994 for the purpose of seeking placement of the Wardenclyffe laboratory-office building and the Tesla tower foundation on both the New York State and NRHP. Its mission is the preservation and adaptive reuse of Wardenclyffe, the century-old laboratory of electrical pioneer Nikola Tesla located in Shoreham, Long Island, New York. In October 1994 a second application for formal nomination was filed. The New York State Office of Parks, Recreation and Historic Preservation conducted inspections and determined the facility meets New York State criteria for historic designation. A second visit was made on February 25, 2009. The site cannot be registered until it is nominated by a willing owner.

Tesla Science Center at Wardenclyffe

Main article: Tesla Science Center at Wardenclyffe

In August 2012, concerned about an apparent offer to purchase the site and develop it for commercial use, The Oatmeal launched a fundraiser for the Tesla Science Center to raise $1.7 million in order to purchase the property, with the hope of eventually building a museum on the grounds. The state of New York agreed to match donations up half that amount. As of October 3, 2012, the goal of $850,000 had been reached in just over six days. A total of $1.37 million was donated, the matching grant from the State of New York brings the total collected to over $2.2 million. The surplus will be used to fund the cleaning and restoration of the property.

Facility grounds

Artistic representation of the station completed, including the tower structure.

Wardenclyffe is located near the Shoreham Post Office and Shoreham Fire House on Route 25A in Shoreham, Long Island, New York. Wardenclyffe was divided into two main sections. The tower, which was located in the back, and the main building compose the entire facility grounds. At one time the property was about 200 acres (0.81 km²). Now it consists of slightly less than 16 acres (65,000 m²).

The wood-framed tower was 186 feet (57 m) tall and the cupola 68 feet (21 m) in diameter. It had a 55-ton steel (some report it was a better conducting material, such as copper) hemispherical structure at the top (referred to as a cupola). Designed by one of Stanford White's associates, the structure was such as to allow each piece to be taken out if needed and replaced as necessary. The transmitter itself was to have been powered by a 200 kilowatt Westinghouse alternating current industrial generator. Beneath the tower, a shaft sank 120 feet (37 m) into the ground. Sixteen iron pipes were placed one length after another 300 additional feet (94.4 m) in order for the machine, in Tesla's words, "to have a grip on the earth so the whole of this globe can quiver."

The main building occupied the rest of the facility grounds. It included a laboratory area, instrument room, boiler room, generator room and machine shop. Inside the main building, there were electromechanical devices, electrical generators, electrical transformers, glass blowing equipment, X-ray devices, Tesla coils, a remote controlled boat, cases with bulbs and tubes, wires, cables, a library, and an office. It was constructed in the style of the Italian Renaissance.

World Wireless System

Transmission of electrical energy without wires

The Tesla coil wireless transmitter
U.S. patent 1,119,732

An electric current flowing through a conductor carries electrical energy. The body of the earth is an electrical conductor, nearly spherical in shape, insulated in space. It possesses an electric charge relative to the upper atmosphere beginning at about 50 kilometers elevation. When a second body, directly adjacent to Earth, is charged and discharged in rapid succession this causes an equivalent variation of Earth's electrostatic charge resulting in the passage of electric current through the ground.

The Tesla coil transmitter, both the single and dual tower forms, is an electrical machine specifically designed to create as large a displacement as possible of Earth's electric charge. It does this by alternately charging and discharging the oscillator's elevated terminal capacitance at a specific frequency, periodically altering the electrostatic charge of the earth, and consequently, with sufficient power, the pressure over its entire surface. "A connection to earth, either directly or through a condenser is essential". The placement of a grounded Tesla coil receiver tuned to the same frequency as the transmitter at another point on the surface results in the flow of electric current through the earth between the two, "while an equivalent electrical displacement occurs in the atmosphere." This current can be used at the receiver to drive an electrical load, which in the case of an individual World Wireless Telecommunications System receiver is a sensitive device using only a small amount of energy.

In 1891 and 1892, Tesla used the oscillatory transformer that bears his name in demonstration lectures delivered before meetings of the American Institute of Electrical Engineers (AIEE) in New York City" and the Institute of Electrical Engineers (IEE) in London. Of two striking results that Tesla demonstrated, one was that the wireless transmission of electrical energy is possible. A later presentation, titled "On Light and Other High Frequency Phenomena" (Philadelphia/St. Louis; Franklin Institute in 1893), is a key event in the invention of radio and can also be said to have begun the development of Wardenclyffe.

One-wire transmission

In the early presentations, the first experiment to be demonstrated was the operation of light and motive devices connected by a single wire to only one terminal of a high frequency induction coil, performed during the 1891 New York City lecture at Columbia College. While a single terminal incandescent lamp connected to one of an induction coil’s secondary terminals does not form a closed circuit “in the ordinary acceptance of the term”, the circuit is closed in the sense that a return path is established back to the secondary by what Tesla called “electrostatic induction” or 'displacement current'. This is due to the lamp’s filament or refractory button capacitance relative to the coil’s free terminal and environment; the free terminal also has capacitance relative to the lamp and environment. At high frequencies, the displacement current through these capacitances is sufficient to light the lamp.

Wireless transmission

Two exhausted tubes are illuminated by a rapidly alternating electrostatic field created between two metallic sheets. A "World Wireless" system for "the transmission of electrical energy" dependent upon Earth's electrical conductivity and electrical coupling through the atmosphere was proposed by Tesla as early as 1904.

The second result demonstrated how energy can be made to go through space without any connecting wires. This was the first step towards a practical wireless system. The wireless energy transmission effect involves the creation of an electric field between two metal plates, each being connected to one terminal of an induction coil’s secondary winding. Once again, a light-producing device (in this case a gas discharge tube) was used as a means of detecting the presence of the transmitted energy. "The most striking result obtained" involved the lighting of two partially evacuated tubes in an alternating electrostatic field while held in the hand of the experimenter. In Tesla's words,

... I suspend a sheet of metal a distance from the ceiling on insulating cords and connect it to one terminal of the induction coil, the other terminal being preferably connected to the ground. Or else I suspend two sheets as illustrated in Fig. 29 / 125, each sheet being connected with one of the terminals of the coil, and their size being carefully determined. An exhausted tube may then be carried in the hand anywhere between the sheets or placed anywhere, even a certain distance beyond them; it remains always luminous.

Here Tesla describes two different types of wireless transmitter, both employing a high-tension induction coil. One has a sheet of metal suspended from the ceiling and connected to one of the induction coil’s terminals, with the other terminal being connected to ground. The other type of transmitter has two sheets of metal suspended from the ceiling, each being connected to one of the coil’s high-voltage terminals.

Theory of wireless transmission

Drawing from U.S. patent 649,621, "Apparatus for Transmission of Electrical Energy" showing the basic Tesla wireless system.

While working to develop an explanation for the two observed effects mentioned above, Tesla recognized that electrical energy can be projected outward into space and detected by a receiving instrument in the general vicinity of the source without the need for any interconnecting wires. He went on to develop two theories related to these observations, which are:

1. By using two Tesla coil transmitter-receivers positioned at distant points on the Earth’s surface, it is possible to induce a flow of electrical current between them.
2. By incorporating a portion of the Earth as part of a powerful dual-elevated-terminal Tesla coil transmitter an electrical disturbance can be impressed upon the Earth and detected “at great distance, or even all over the surface of the globe.”

Tesla also made the assumption that the Earth is a charged body floating in space.

A point of great importance would be first to know what is the capacity of the Earth? and what charge does it contain if electrified? Though we have no positive evidence of a charged body existing in space without other oppositely electrified bodies being near, there is a fair probability that the Earth is such a body, for by whatever process it was separated from other bodies—and this is the accepted view of its origin—it must have retained a charge, as occurs in all processes of mechanical separation.

Tesla was familiar with demonstrations that involved the charging of Leyden jar capacitors and isolated metal spheres with electrostatic influence machines (in modern terms, high-voltage (kV), low-current (μA) electrostatic generators). By bringing these elements into proximity with each other, and also by making direct contact followed by their separation, the charge can be manipulated. He surely had this in mind in the creation of his mental image, not being able to know that the model of Earth’s origin was inaccurate. The presently accepted model of planetary origin is one of accretion and collision.

If it be a charged body insulated in space its capacity should be extremely small, less than one-thousandth of a farad.

We now know that the Earth is a charged body, made so by processes—at least in part—related to the interaction between the continuous stream of charged particles called the solar wind that flows outward from the center of our solar system and Earth’s magnetosphere.  We also know that Tesla's capacitance estimate was essentially correct: Earth's self-capacitance is about 710 microfarads.

But the upper strata of the air are conducting, and so, perhaps, is the medium in free space beyond the atmosphere, and these may contain an opposite charge.  Then the capacity might be incomparably greater.

We also know that Earth's upper atmospheric strata are conducting, or can be made so.

In any case it is of the greatest importance to get an idea of what quantity of electricity the Earth contains.

An additional condition of which we are now aware is that the Earth possesses a naturally existing negative charge with respect to the conducting region of the atmosphere beginning at an elevation of about 50 km.  The potential difference between the Earth and this region is on the order of 400,000 volts.  Near the Earth's surface there is a ubiquitous downward directed E-field of about 100 V/m.  Tesla referred to this charge as the “electric niveau” or electric level.

It is difficult to say whether we shall ever acquire this necessary knowledge, but there is hope that we may, and that is, by means of electrical resonance.  If ever we can ascertain at what period the Earth's charge, when disturbed, oscillates with respect to an oppositely electrified system or known circuit, we shall know a fact possibly of the greatest importance to the welfare of the human race.  I propose to seek for the period by means of an electrical oscillator, or a source of alternating electric currents. .

Some maintain the 200 kW wireless facility would have functioned by the production and propagation of electromagnetic radiation also known as the transverse electromagnetic (TEM) radio wave, but this is not the case.

I am not producing radiation in my system; I am suppressing electromagnetic waves.  But, on the other hand, my apparatus can be used effectively with electromagnetic waves.  The apparatus has nothing to do with this new method except that it is the only means to practice it.  So that in my system, you should free yourself of the idea that there is radiation, that energy is radiated.  It is not radiated; it is conserved.

By Tesla's own account, the earth resonance system works by the creation of "powerful disturbances" in Earth's natural electric charge. The Wardenclyffe facility had a dual purpose.  In addition to point-to-point telecommunications and broadcasting it was also intended to demonstrate the transmission of electrical power on a reduced scale.  He stated,

It is intended to give practical demonstrations of these principles with the plant illustrated.  As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere.  He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment.  An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant.  In the same manner any picture, character, drawing, or print can be transferred from one to another place.  Millions of such instruments can be operated from but one plant of this kind.  More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction.

Wardenclyffe was the first of many installations to be constructed near major population centers around the world.  If plans had moved forward without interruption the Long Island prototype would have been followed by a second plant built in the British Isles, perhaps on the west coast of Scotland near Glasgow.  Each of these facilities would include a large magnifying transmitter of a design loosely based upon the apparatus assembled at the Colorado Springs Experimental Station in 1899.

"... The plant in Colorado was merely designed in the same sense as a naval constructor designs first a small model to ascertain all the quantities before he embarks on the construction of a big vessel.  I had already planned most of the details of the commercial plant, subsequently put up at Long Island, except that at that time the location was not settled upon.  The Colorado plant I have used in determining the construction of the various parts, and the experiments which were carried on there were for the practical purpose of enabling me to design the transmitters and receivers which I was to employ in the large commercial plant subsequently erected..."

Using a global array of these magnifying transmitters, it was Tesla's plan to establish what he called the "World Wireless System," providing multi-channel global broadcasting, an array of secure wireless telecommunications services, and a long range aid to navigation, including means for the precise synchronization of clocks.  In a more highly developed state he envisaged the 'World System' would expand to include the wireless industrial transmission of electric power.

At the time the power grid was quite limited in terms of reach and the Wardenclyffe prototype represented a way to significantly reduce the cost of "electrifying" the countryside.  This wireless technique was called the "disturbed charge of ground and air method".

There is evidence that Wardenclyffe would have used extremely low frequency signals combined with higher frequency signals.  In practice, the transmitter electrically influences both the Earth and the space above it.

The process is essentially the same as transmitting electricity by conduction through a wire.  The earth itself is one of the conducting media involved in ground and air system technology.  The other medium is the atmosphere above approximately 3 miles (4.8 km) elevation.  While not an ohmic conductor, in this region of the troposphere and upwards, the density or pressure is sufficiently reduced to so that, according to theory, the atmosphere’s insulating properties can be easily impaired thus allowing an electric current to flow.  Theory further states that the conducting region is developed through the process of atmospheric ionization in which the affected portions thereof are changed to plasma.  The presence of the magnetic fields developed by each plant’s helical resonator suggests that an embedded magnetic field and flux linkage is also involved.  Flux linkage with Earth’s natural magnetic field is also a possibility, especially in the case of an earth resonance transmission system.

Means for long conductors of electricity forming part of an electric circuit and electrically connecting said ionized beam to an electric circuit. Hettinger 1917 -(U.S. patent 1,309,031)

The atmosphere below 3 miles (4.8 km) is also a propagating medium for a portion of the above-ground circuit.  Being an insulating medium, electrostatic induction is involved rather than true electrical conduction.  The practical construction limitation imposed upon the height of the elevated terminals can be overcome with a sufficiently high electrical potential.  A highly energetic transmitter, as was intended at Wardenclyffe, charges the elevated terminal to the point where the atmosphere around and above the facility breaks down and becomes ionized.  This leads to a flow of true conduction currents between the two terminals by a path up to and through the upper atmosphere, and back down to the other facility.  The ionization of the atmosphere directly above the elevated terminals can be facilitated by the use of ionizing beams of ultraviolet radiation to form what might be called high-voltage plasma transmission lines.  [ed. see also, longitudinal waves and waves in plasmas.]

In various writings, Tesla explained that the Earth itself behaves as a resonant LC circuit when it is electrically excited at certain frequencies. At Wardenclyffe he operated at frequencies ranging from 1,000 Hz to 100 kHz. Tesla found the frequency range up to 30 – 35 kHz “to be most economical.” Excitation of earth resonance at a harmonic of the 11.78 Hz fundamental frequency suggests energy transmission by means of a TM₀₀ spherical conductor “single-wire” surface wave transmission line mode. A Schumann resonance mode (the fundamental frequency being about 7.5 to 7.9 Hz) is probably not involved. The entire Earth can be electrically resonated with a single earth-resonance transmitter, so an earth-resonance based system would require, at a minimum, that only one World Wireless System transmitter be constructed. Alternatively, two distantly spaced transmiter-receiver facilities could be constructed. Such a system would not be so dependent upon the excitation of an earth-resonance mode. In either case a surface wave, similar to the Zenneck wave would be used. Artificially induced earth currents would be used. According to Tesla, the planet's large cross-sectional area provides a low resistance path for the flow of earth currents. The greatest losses are apt to occur at the points where the transmitting / receiving plants and dedicated receiving stations are connected with the ground. This is why Tesla stated;

You see the underground work is one of the most expensive parts of the tower. In this system that I have invented it is necessary for the machine to get a grip of the Earth, otherwise it cannot shake the Earth. It has to have a grip on the Earth so that the whole of this globe can quiver, and to do that it is necessary to carry out a very expensive construction.

To close the circuit a second path is established between the two transmitter-receiver plants' elevated high-voltage terminals through the rarefied atmospheric strata above 3 miles (4.8 km).  The connection is made by some combination of electrostatic induction and electrical conduction through plasma. While a number of his wireless patents, including "Apparatus for transmitting electrical energy," U.S. Patent No. 1,119,732, December 1, 1914, describe a system which uses the plasma-conduction scheme, his "Art of transmitting electrical energy through the natural mediums," U.S. Patent No. 787,412, April 18, 1905 and some of his Wardenclyffe design notes from 1901 show the overall plan also involves electrostatically induced oscillations in the potential associated with Earth's self-capacitance. The two tower earth-resonance transmitter is especially designed for this purpose. Tesla wrote,

The specific plan of producing the stationary waves, here-in described, might be departed from. For example, the circuit which impresses the powerful oscillations upon the earth might be connected to the latter at two points.

Tesla believed that a fully developed system with large high-power stations based upon the smaller Wardenclyffe prototype would permit wireless transmission and reception across large distances with negligible losses.

In the course of this work, I mastered the technique of high potentials sufficiently for enabling me to construct and operate, in 1899, a wireless transmitter developing up to twenty million volts. Some time before I contemplated the possibility of transmitting such high tension currents over a narrow beam of radiant energy ionizing the air and rendering it, in measure, conductive. After preliminary laboratory experiments, I made tests on a large scale with the transmitter referred to and a beam of ultra-violet rays of great energy in an attempt to conduct the current to the high rarefied strata of the air and thus create an auroral such as might be used for illumination, especially of oceans at night. I found that there was some virtue in the principal but the results did not justify the hope of important practical applications....

In spite of ridicule, many of Tesla's ideas have been demonstrated to be essentially correct. For example he correctly predicted the existence of the ionosphere and electrical resonance of the Earth-atmosphere system. Resonance of the earth-ionosphere cavity with a fundamental frequency in the vicinity of 7.3 Hz was demonstrated in the 1950s as the Schumann resonance. The latter phenomenon was named after Schumann, for although Tesla had detected a resonance of the Earth-atmosphere system, he was not taken seriously in his time. Furthermore, Tesla appears to have excited a different terrestrial resonance mode with a fundamental frequency of 11.78 Hz.

Electrical transmission and reception

Tesla's early experiments involved the propagation of ordinary radio waves, that is to say Hertzian waves, electromagnetic waves propagated through space without artificial guide.

In 1919 Tesla wrote,

The popular impression is that my wireless work was begun in 1893, but as a matter of fact I spent the two preceding years in investigations, employing forms of apparatus, some of which were almost like those of today. It was clear to me from the very start that the successful consummation could only be brought about by a number of radical improvements. Suitable high frequency generators and electrical oscillators had first to be produced. The energy of these had to be transformed in effective transmitters and collected at a distance in proper receivers. Such a system would be manifestly circumscribed in its usefulness if all extraneous interference were not prevented and exclusiveness secured. In time, however, I recognized that devices of this kind, to be most effective and efficient, should be designed with due regard to the physical properties of this planet and the electrical conditions obtaining on the same.

One of the requirements of the World Wireless system is the construction of resonant receivers. The grounded helical resonator of a Tesla Coil and an elevated terminal can be used in receive mode. Tesla himself repeatedly demonstrated the wireless transmission of electrical energy from a Tesla coil transmitter to a Tesla coil receiver. These concepts and methods are part of his wireless transmission system (US1119732 – Apparatus for Transmitting Electrical Energy – January 18, 1902). Tesla made a proposal that there would be many more than thirty transmission-reception stations worldwide.

Tesla coil in one experiment of many conducted in Colorado Springs. This is a grounded tuned coil in resonance with a distant transmitter; Light is glowing near the bottom.

In the principle form of Tesla system receiver, a Tesla coil receiving transformer acts as a step-down transformer with high current output. The parameters of a Tesla Coil transmitter are identically applicable to it being a receiver (e.g.., an antenna circuit), due to reciprocity.

[Impedance, generally though, is not applied in an obvious way; for electrical impedance, the impedance at the load (e.g.., where the power is consumed) is most critical and, for a Tesla Coil receiver, this is at the point of utilization (such as at an induction motor) rather than at the receiving node. Complex impedance of an antenna is related to the electrical length of the antenna at the wavelength in use. Commonly, impedance is adjusted at the load with a tuner or a matching networks composed of inductors and capacitors.]

In another form of receiving circuit the two input terminals are connected to a device designed to reverse polarity at predetermined intervals of time and charge a capacitor.  This form of Tesla system receiver has means for commutating the current impulses in the charging circuit so as to render them suitable for charging an energy storage device, a device for closing the receiving-circuit, and means for causing the receiver to be operated by the accumulated energy.

The intention of the Tesla world wireless energy transmission system is to combine electrical power transmission along with broadcasting and point-to-point wireless telecommunications, and allow for the elimination of many existing high-tension power transmission lines, facilitating the interconnection of electrical generation plants on a global scale.

One of Tesla's patents suggests he may have misinterpreted 25–70 km nodal structures associated with cloud-ground lightning observations made during the 1899 Colorado Springs experiments in terms of circumglobally propagating standing waves instead of a local interference phenomenon of direct and reflected waves.

Regarding the recent notion of power transmission through the earth-ionosphere cavity, a consideration of the earth-ionosphere or concentric spherical shell waveguide propagation parameters as they are known today shows that wireless power transmission by direct excitation of a Schumann cavity resonance mode is not realizable. "The conceptual difficulty with this model is that, at the very low frequencies that Tesla said that he employed (1–50 kHz), earth-ionosphere waveguide excitation, now well understood, would seem to be impossible with either the Colorado Springs or the Long Island apparatus (at least with the apparatus that is visible in the photographs of these facilities)."

On the other hand, Tesla's concept of a global wireless electrical power transmission grid and telecommunications network based upon energy transmission by means of a spherical conductor transmission line with an upper three-space model return circuit, while perhaps not practical for power transmission, is feasible, defying no law of physics. Global wireless transmission by means of a spherical conductor “single-wire” surface wave transmission line and a propagating TM₀₀ mode may also be possible, a feasibility study using a sufficiently powerful and properly tuned Tesla coil earth-resonance transmitter being called for.

Common misconceptions

Propagation mode

It was once thought the 200 kW Wardenclyffe prototype World Wireless station would have functioned by the production and propagation of electromagnetic radiation also known as the transverse electromagnetic (TEM) radio wave, but this is not the case. The World Wireless System actually works by the creation of powerful disturbances in the Earth's natural electric charge and TM₀₀ mode propagation over a spherical single conductor transmission line. {{citation}}: Empty citation (help)

I am not producing radiation in my system; I am suppressing electromagnetic waves. But, on the other hand, my apparatus can be used effectively with electromagnetic waves. The apparatus has nothing to do with this new method except that it is the only means to practice it. So that in my system, you should free yourself of the idea that there is radiation, that energy is radiated. It is not radiated; it is conserved.

World System functionality

It is believed by some that World Wireless System technology is intended only for wireless power transmission. The prototype Wardenclyffe installation and the second facility planned in Scotland had a dual purpose. Their primary function was worldwide broadcasting and multi-channel point-to-point trans-Atlantic wireless telecommunications. The prototype system was also intended for proof-of-concept wireless power transmission demonstrations, although on a greatly reduced scale.

It is intended to give practical demonstrations of these principles with the plant illustrated. As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place. Millions of such instruments can be operated from but one plant of this kind. More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction.

{{citation}}: Empty citation (help)

Schumann Cavity resonance hypothesis

It has been proposed the World Wireless System involve energy transfer by means of a concentric spherical shell waveguide composed of Earth's surface and the ionosphere. This is known as the Schumann Cavity. Natural lightning excites Schumann resonances that are observed at the lowest few resonance frequencies (about 8 Hertz and multiples of that). Their measured Q's of order 5 to 10 suggest that the electrical disturbances produced by lightning make a few circuits of the Earth before damping out, and create a fairly definite terrestrial standing wave of a few cycles duration.

The conceptual difficulty with this model is that, at the very low frequencies that Tesla said that he employed (1–50 kHz), earth-ionosphere waveguide excitation, now well understood, would seem to be impossible with the either the Colorado Springs or the Long Island apparatus (at least with the apparatus that is visible in the photographs of these facilities).

The maximum recommended operating frequencies of 25 kHz as specified by Tesla is far above the highest easily observable Schumann resonance mode (this is the 9th overtone) that exists at approximately 66.4 Hz. Tesla's selection of 25 kHz is wholly inconsistent with the operation of a system that is based upon the direct excitation of a Schumann resonance mode.

Ionospheric conduction

It is believed by some the atmospheric path used in the two-conductor method, i.e., the "second path," is the ionosphere, the uppermost strata of Earth's atmosphere starting at approximately 30 miles (48 km) in daytime and approximately 55 miles (89 km) at night. The atmospheric strata through which energy can be transmitted has a barometric pressure of 75 mm, equivalent to an elevation of about 15 miles (24 km). World Wireless System apparatus allows this elevation to be reduced down to approximately 4.5 miles (7.2 km) because of the exceedingly high potentials involved.

Variant receiver

A variant was suggested by Tesla for exploiting the vertical voltage gradient in the Earth's atmosphere.

A variant was suggested that could use the phantom loop effect to form a circuit to induct energy from the Earth's magnetic field and other radiant energy sources (including, but not limited to, electrostatics).

A Tesla Coil can receive electromagnetic impulses from atmospheric electricity and radiant energy, besides normal wireless transmissions.

The charging-circuit can be adapted to be energized by the action of various other disturbances and effects at a distance. Arbitrary and intermittent oscillations that are propagated via conduction to the receiving resonator will charge the receiver's capacitor and use the potential energy to greater effect.

Various radiations can be used to charge and discharge conductors, with the radiations considered electromagnetic vibrations of various wavelengths and ionizing potential.

Radiant energy throws off with great velocity minute particles which are strongly electrified and other rays falling on the insulated-conductor connected to a condenser (i.e., a capacitor) can cause the condenser to indefinitely charge electrically.

The helical resonator can be "shock excited" due to radiant energy disturbances not only at the fundamental wave at one-quarter wavelength but also is excited at its harmonics.

The output power from these devices, attained from Hertzian methods of charging, is low, but alternative charging means are available.

Hertzian methods can be used to excite a receiver with limitations that result in great disadvantages for utilization, though. The methods of ground conduction and the various induction methods can also be used to excite the receiver, but are again at a disadvantages for utilization.

The receiver uses the effects or disturbances to charge a storage device with energy from an external source (natural or man-made) and controls the charging of said device by the actions of the effects or disturbances (during succeeding intervals of time determined by means of such effects and disturbances corresponding in succession and duration of the effects and disturbances). The stored energy can also be used to operate the receiving device. The accumulated energy can, for example, operate a transformer by discharging through a primary circuit at predetermined times which, from the secondary currents, operate the receiving device.

With regard to Tesla's statements on the harnessing of natural phenomena to obtain electric power, he stated:

Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe. — "Experiments with Alternate Currents of High Potential and High Frequency" (February 1892)

Particle beam invention

Main articles: Teleforce, Particle beam weapon, and Directed-energy weapon

Related to the operation and utilization of Wardenclyffe Tower was Tesla's work in the 1930s on a macroscopic charged particle beam weapon called Teleforce. A Wardenclyffe-style facility that included the weapon was contemplated. He offered it to Westinghouse Electric & Manufacturing Company in early 1934. It was also offered to the US War Department, Great Britain, and Yugoslavia. A descriptive 17-page type-written document on Tesla's office letterhead titled, "New Art of Projecting Concentrated Non-Dispersive Energy Through Natural Media", which presently exists in the Nikola Tesla Museum archive in Belgrade, shows that his macroscopic particle beam, also dubbed the "Peace Ray" or the "death ray" by contemporary media, was a narrow stream of charged macroscopic clusters of atomic mercury or tungsten accelerated by high voltage, produced by either a huge Van de Graaff generator or Tesla Coil.

Telefunken Station

After Wardenclyffe, Tesla built the Telefunken Wireless on the South Shore of Long Island. Some of what he wanted to achieve at Wardenclyffe was achieved with the Telefunken Wireless. In West Sayville, Long Island, New York, Tesla assisted in the building of three 600-foot (180 m) radio towers, creating the western wireless communication station in a North America and Europe network.

Tesla quotations

• "As soon as [the Wardenclyffe facility is] completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place ..." – "The Future of the Wireless Art," Wireless Telegraphy and Telephony, 1908, pg. 67–71.

• "It is not a dream, it is a simple feat of scientific electrical engineering, only expensive – blind, faint-hearted, doubting world! [...] Humanity is not yet sufficiently advanced to be willingly led by the discoverer's keen searching sense. But who knows? Perhaps it is better in this present world of ours that a revolutionary idea or invention instead of being helped and patted, be hampered and ill-treated in its adolescence – by want of means, by selfish interest, pedantry, stupidity and ignorance; that it be attacked and stifled; that it pass through bitter trials and tribulations, through the strife of commercial existence. So do we get our light. So all that was great in the past was ridiculed, condemned, combatted, suppressed – only to emerge all the more powerfully, all the more triumphantly from the struggle." – "The Transmission of Electrical Energy Without Wires as a Means for Furthering Peace," Electrical World and Engineer, January 7, 1905.

Related patents

Tesla's patents

Main article: List of Nikola Tesla patents

• "Means for Generating Electric Currents," U.S. patent 514,168, February 6, 1894
• "Electrical Transformer," U.S. patent 593,138, November 2, 1897
• "Method Of Utilizing Radiant Energy," U.S. patent 685,958 November 5, 1901
• "Method of Signaling," U.S. patent 723,188, March 17, 1903
• "System of Signaling," U.S. patent 725,605, April 14, 1903
• "Art of Transmitting Electrical Energy Through the Natural Mediums," U.S. patent 787,412, April 18, 1905
• "Apparatus for Transmitting Electrical Energy," January 18, 1902, U.S. patent 1,119,732, December 1, 1914

See also

• Wireless energy transmission
• Transmission medium
• Distributed generation
• Electricity distribution
• Electric power transmission
• Friis transmission equation
• Terrestrial stationary waves
• Devices: Tesla coil, Magnifying Transmitter, Electro-mechanical oscillator

Further reading

• Anderson, Leland, "Rare Notes from Tesla on Wardenclyffe" in Electric Spacecraft – A journal of Interactive Research, Issue 26, September 14, 1998. Contains copies of rare documents from the Tesla Museum in Belgrade including Tesla's notes and sketches from 1901
• Bass, Robert W., "Self-Sustained Non-Hertzian Longitudal Wave Oscillations as a Rigorous Solution of Maxwell's Equations for Electromagnetic Radiation". Inventek Enterprises, Inc., Las Vegas, Nevada.
• "Boundless Space: A Bus Bar". The Electrical World, Vol 32, No. 19.
• Massie, Walter Wentworth, "Wireless telegraphy and telephony popularly explained ". New York, Van Nostrand. 1908.
• Rather, John, "Tesla, a Little-Recognized Genius, Left Mark in Shoreham". The New York Times. Long Island Weekly Desk.
• Tesla, Nikola, "The Transmission of Electrical Energy Without Wires", Electrical World and Engineer, March 5, 1904.
• Tesla, Nikola, "World System of Wireless Transmission of Energy", Telegraph and Telegraph Age, October 16, 1927.

External links

• PBS Tower of Dreams the wireless global communications]
• Wardenclyffe Tower at Structurae
• Tesla Science Center at Wardenclyffe