This invention started from what Tesla called Teleforce, an idea Tesla said he conceived after studying the Van de Graaf generator, an electrostatic machine that uses a moving belt to accumulate large amounts of electrical charge in the interior of a hollow metal sphere. The production of X-rays or experiments in particle physics and nuclear physics could be applied with the generator.

According to Tesla, the particle beam weapon, also known as “death ray” or “peace ray”, was a weapon that would be capable of being used against an entire ground infantry or for anti-aircraft purposes. This single weapon would be so powerful that it would be able to destroy anything that is in a radius of 300 to 400 kilometres. This would have proved to be particularly useful in preventing wars, as it would be able to put an end to it before it starts at all.

Tesla’s Latest Results – He Now Produces Radiographs at a Distance of More Than Forty Feet – Electrical Review – March 18th, 1896:

“I am producing strong shadows at distances of 40 feet. I repeat, 40 feet and even more. Nor is this all. So strong are the actions on the film that provisions must be made to guard the plates in my photographic department, located on the floor above, a distance of fully 60 feet, from being spoiled by long exposure to the stray rays. Though during my investigations I have performed many experiments which seemed extraordinary, I am deeply astonished observing these unexpected manifestations, and still more so, as even now I see before me the possibility, not to say certitude, of augmenting the effects with my apparatus at least tenfold!”

“These effects upon the sensitive plate at so great a distance I attribute to the employment of a bulb with a single terminal, which permits the use of practically any desired potential and the attainment of extraordinary speeds of the projected particles. With such a bulb it is also evident that the action upon a fluorescent screen is proportionately greater than when the usual kind of tube is employed, and I have already observed enough to feel sure that great developments are to be looked for in this direction”.

Between the 1920s and 1930s, there were, in addition to Tesla, other inventors such as Marconi, Matthews or Edwin R. Scott who claimed to have invented the weapon. In 1923 Edwin R. Scott claimed to be the first to develop a death ray with the ability to destroy even aircraft at a great distance. Scott claimed that he worked a decade on the artefact.

A year later Harry Matthews appeared trying to sell to the British Air Ministry what he defined as a death ray. The truth is that none of them was able to show an operating model.

Soon Tesla would arrive on the scene at the beginning of the 1930s. The genius affirmed to have invented the “death ray” under the name of Teleforce and maintained the claim of such achievement until the end of his days. Earlier, in the mid-1910s, Tesla had already spoken of a weapon that would mark the beginning of the end of wars as they knew it. Tesla spoke about the end of gunpowder due to armed conflicts marked by electricity, a time where “his” cannon would be the ultimate weapon.

Years after the fall of the Wardenclyffe Tower, with Tesla living between his great genius and inventiveness and his economic problems, he kept looking for a way to make his particle beam theory something of great importance. To do this, he went on to imagine the invention with military applications.

The idea was to get some department to accept the project he had in his head. This was the reason why his dedication and efforts thereafter were directed to the service of the military. In 1934, when Tesla described the function of the weapon and the reason for its construction, he emphasized that he was all about peace.

Until then, all devices that could be used for defence could also be used for the sake of aggression. This nullified the value of making improvements for the purpose of peace. Tesla developed a new idea that can be used mainly for defence.

If successful and adopted, it would have revolutionized relations between nations. It would have made any country, large or small, impregnable to armies, airplanes and other means of combat. Tesla’s invention required great machinery and lots of resources, but once achieved it would have been able to destroy anything.

The Soviet Union actually invested $25,000 into the idea, asking for an exchange of plans and ideas. Upon the declassification of Tesla’s documents seized by the U.S. intelligence upon is death, it became clear that even the U.S. Government was interested, among other governments.

In 1907, when commenting on the destruction of the French ship Iena, Tesla noted in a letter to the New York Times that he has built and tested remotely controlled torpedoes, but that electrical waves would be more destructive:

“As to projecting wave energy to any particular region of the globe, this can be done by my devices,” he wrote. Further, he claimed that “the spot at which the desired effect is to be produced can be calculated very closely, assuming the accepted terrestrial measurements to be correct.”

In 1908 Tesla repeated the idea of destruction by electrical waves to the newspaper on April 21st His letter to the editor stated:

“When I spoke of future warfare I meant that it should be conducted by direct application of electrical waves without the use of aerial engines or other implements of destruction.” He added: “This is not a dream. Even now wireless power plants could be constructed by which any region of the globe might be rendered uninhabitable without subjecting the population of other parts to serious danger or inconvenience.”

Again in 1915, in another letter to the editor, Tesla stated:

“It is perfectly practical to transmit electrical energy without wires and produce destructive effects at a distance. I have already constructed a wireless transmitter which makes this possible. When unavoidable, the [transmitter] may be used to destroy property and life.”