Tesla's entire adult life was dedicated to the task of designing and improving devices for, as he put it, "the service of mankind."  During Dr. Tesla's long career he invented many things that truly changed the way in which we all live, and literally made possible the tremendous productivity of American industry in the twentieth century.  His first major contributions to society were in the area of electrical power system design.

The advantages that alternating currents held in their ease of generation and transmission were readily apparent.  The major obstacle that lay in the path to the use of alternating current on a large scale, however, was the absence of a practical AC electric motor.  In 1882 Tesla, who had realized that AC held the key to an efficient power distribution system, successfully designed the needed motor.  His demonstration of the 1/5 horsepower two-phase motor at Columbia University on May 16, 1888, before the American Institute of Electrical Engineers, helped to usher in a new era of inexpensive and abundant electrical energy.

By 1892 the U.S. Patent office had issued Tesla over 40 patents based upon his rotating magnetic field principle, covering what is known as the Polyphase Power System.  By mid-1895 the world's first commercial hydroelectric AC power plant was in operation at Niagara Falls, New York.  The nameplates on the massive generators that were installed there bore the name of Nikola Tesla.  To this day, virtually every single electric induction motor in use around the world is based upon one of Tesla's original designs.

Tesla's polyphase or three phase alternating current power system is presently used to generate, transmit, and in the case of large motors, utilize essentially all of our electric power.  And, this is only one of the contributions this little known and seldom recognized inventor gave to the world.  It is only now becoming general knowledge that Nikola Tesla also originated and built all of the basic circuits required for the transmission and reception of wireless communications—what we call radio and broadcast television.

He first demonstrated radio transmission and reception in 1893, two years before Marconi, and operated a radio controlled boat, the telautomaton, at Madison Square Garden in 1898.  He knew that in addition to Morse code and remote control the sound of a human voice, music, and images could also be transmitted with his system.  The fact that Tesla is the true inventor of radio is supported by a 1943 ruling of the United States Supreme Court in which he was posthumously acknowledged as having priority over Guglielmo Marconi in regards to the fundamental radio patents.

It is interesting to note the high power oscillator he designed for use as a wireless transmitter also evolved into the high voltage power supply which operates our present day television cathode ray picture tubes.

In the spring of 1899, shortly after receiving a request from an office of the U.S. Government to develop a wireless communications system, Tesla moved his work to a high plateau near Colorado Springs.  There he constructed a large experimental radio station unlike anything the world had ever seen before.  His plan was to study the characteristics of high voltage, high frequency alternating electrical currents with the intellectual goal of ascertaining "the laws of propagation of currents through the earth and the atmosphere."  His first task was to develop an extremely powerful transmitter and perfect a method by which the transmitted energy could be channelized, or using his word, "individualized."  At the same time he developed a number of sophisticated receivers "for individualizing and isolating the energy transmitted" that would allow a transmitter's signals to be selectively tuned in.  What followed was a series of important experiments that vastly increased man's knowledge of radio propagation and earth resonance, culminating nearly a decade of work related to the study of synchronized electrical tuned circuits.

The successes achieved in Colorado led Tesla to an absolute conviction that wireless communication to any point on the globe was possible by the help of the devices he had perfected.  This set the stage for Tesla's next grand feat—establishment of an international radio broadcasting facility that was to become known as Wardenclyffe.

In December of 1900, after wrapping up his preliminary testing, he returned to New York to begin work on the full sized prototype worldwide broadcasting station.  The main structure, built to house equipment for this station and known as the Wardenclyffe Powerplant/Office Building, is still standing near the Long Island community of Shoreham, New York.  While not a great amount has been learned about the station's specific design details, it is quite certain that there would have been major similarities between it and the large 1899 apparatus.  An important document which bears this out is Tesla's U.S. Patent No. 1,119,732 an "Apparatus For Transmitting Electrical Energy."  An accompanying drawing of a Wardenclyffe-type transmitter shows the completed Long Island facility would have incorporated the full three-coil "magnifying transmitter" configuration that was refined in Colorado.

Tesla's research at Wardenclyffe was brought to an end due to a lack of funding.  The building was abandoned and Tesla's tower was eventually demolished during the early years of World War I.  One interesting feature of Tesla's World System for global communications, had it gone into full operation, would have been a purported capacity to provide small but usable quantities of electrical power at the location of the receiving circuits.  He envisioned further advances that would have permitted the wireless transmission of electrical power in industrial amounts to any point on the earth's surface with minimal losses.  If the prototype communications station on Long Island had demonstrated the feasibility of wireless power transmission then the pilot plant for this larger system would have been located at Niagara Falls, site of the first commercial three-phase AC power plant mentioned earlier.

Everyone has heard of RADAR, but few people know that the men who built the first primitive RADAR units in 1934 were following principles, mainly regarding frequency and power level, that were first mentioned by Tesla in 1917.

Also included in the list of the Nikola Tesla's many inventions may be found a variety of novel electric lamps, all of which were designed to operate in conjunction with specially designed high frequency power supply units. Some of these lamps were forerunners of our present day fluorescent tubes.  In fact, not long ago a small California company announced the development of a high frequency electronically powered fluorescent bulb, dubbed the E-Lamp, which bears a striking resemblance to a bulb that Tesla designed and built nearly one hundred years ago.  The principle upon which they both work is identical.  Another type of lamp was essentially the same as the slender neon filled tubes that are now commonly bent into the shapes of letters and used in storefront advertising.  A third type of electric lamp that Tesla designed, known as the incandescent carbon button lamp, was capable of producing light at very high levels of efficiency.  A variation on the design of this lamp is embodied in the popular Plasma Globe novelty item.  Another lamp that he patented in 1891 under the name "Electric Incandescent Lamp" has been adopted by the United States Armed Forces as part of a portable high intensity lighting system.  The lamp itself consists of a tiny spark gap enclosed within a small gas-filled glass bulb.

Tesla's study of high voltage, high frequency alternating currents resulted in many observations of the physiological effects that were found to be associated with this type of electricity.  A type of therapeutic device, based on his discoveries in the area of inductive heating, came to be known as the diathermy machine. His work with high frequency electric lamps lead to the development of a large variety of vacuum tubes, some of which had medical applications: He developed instruments for the generation of X rays and techniques for their use to photographically image living tissue; An implement known as the Violet Ray device was also forthcoming, it having applications in thermic and oxygen therapy; One of his tubes has even been recognized as a primitive forerunner of the modern day electron microscope.

In addition, he pioneered the use of ozone for the treatment of water, a technique which is once again becoming popular because of its benign nature and the fact that no chlorine or other dangerous chemicals are needed.

Tesla's discoveries also form part of the foundation of the medical field known as Nuclear Magnetic Resonance imaging.  In fact, in 1960 the official standard unit of magnetic flux density was designated the "tesla", thus placing him among an exclusive group of outstanding world-class scientists such as Volta, Ampere, Faraday, Henry, Kelvin, Roentgen and Curie.

Another one of Tesla's inventions, familiar to anyone who has ever owned an automobile, was patented in 1898 under the name "Electrical Igniter For Gas Engines."  More commonly known as the automobile ignition system, its primary component, the ignition coil, remains essentially unchanged since its introduction into use at the turn of the century.

In addition to designing the first practical automobile ignition system, Nikola Tesla also designed and built prototypes of a unique fuel-burning rotary engine.  It consists of multiple shaft-mounted steel disks suspended on bearings within a cylindrical housing.  In operation, high velocity gases enter at the periphery of the disks, and flow between them in free spiral paths to finally escape through central exhaust ports depleted of energy.  Instead of extracting energy from the gas through an action on pistons, blades or vanes, Nikola Tesla's disk turbine depends upon the properties of adhesion and viscosity to achieve this result.  The slight density of the gas and its attraction to the faces of the disks combined to efficiently transmit the fuel's energy to the disks and thence to the shaft.

Recent tests carried out on the Tesla disk turbine indicate that when constructed in strict accordance with Tesla's design specifications it might rank as the world's most efficient gas engine.  It could out-perform our present day piston type internal combustion engines in many ways such as fuel economy, longevity, adaptability to different fuels, cost of manufacture and power to weight ratio.  Indeed, this machine has been described as the perfect rotary engine.

Many people are aware that a device such as a piston engine can reverse its role and act as a pump. This is the case with the Tesla turbine.  In fact the design has already proven itself in a wide range of applications in the area of pump technology. The pump's ability to handle corrosive materials is one design feature that carries over into the turbine, in that it will be able to operate for extended periods of time on corrosive fuels and propellants, such as gasoline, coal, gasified biomass and wet steam, that tend to damage certain internal components of conventional engines.  The Tesla Disk Turbine would also be ideal for use with propane, natural gas or hydrogen as its fuel.

Nikola Tesla dreamt of a better world in which all work was performed in the most efficient and harmonious manner possible.  AC power, radio communications, high-frequency fluorescent lighting and some of the other technological innovations described above are familiar and vital components to life which are serving to fulfill this vision.  Even in light of these things' significance, the other, and for the most part unused, inventions which he gave to the world have the capacity to be of an equivalent or perhaps even greater value to society.  As the years went by, it seems that Tesla began to accept the fact that circumstances would not allow for the immediate adoption of his more advanced ideas.  With his passing on January 7, 1943 all direct opportunity to learn about those advanced technologies was lost.  We are fortunate, however, to have inherited a large volume of material that relates specifically to these designs.  The primary source of knowledge is what might be called the "Tesla canon."  This includes his lectures and patents which have been published in book form.  Additional sources are old newspapers and periodicals that reside in the archives of America's libraries, and also the files of old legal firms that were active during his time.  More information is to be found in Belgrade, Yugoslavia at the Muzej Nikole Tesle (Nikola Tesla Museum) that was established in the mid-1950s to hold artifacts and papers that were shipped there a few years after Tesla's death.  In spite of the fact that some information appears to have been lost, the basic simplicity of the design principles involved assures their survival.

It is hoped the scientific and engineering communities at large can be persuaded to initiate dedicated research programs that will result in full restoration of this vital knowledge.  Such a thing can happen, but with the scant mention of Tesla's work in the curricula of our learning institutions this task might be a difficult one.  There are things that can be done right away by schools, manufacturers, and the public at large that will speed up the reintegration process.  Credit could be given where credit is due for the inventions that have long been incorporated into the very fabric of our daily lives.  Also, Tesla's less controversial designs, which have been made available but not widely utilized, could be developed and introduced into the public and private sectors.

Once our scientists and engineers are convinced of the overall validity of his designs through a practical hands-on understanding of them, then perhaps the work of bringing Nikola Tesla's vision closer to reality will accelerate.