The (Shocking) History & Physics of Electric Transformers

History of electric transformers from Faraday through Lenz, Sturgeon, Callan, Ruhmkorff, Gaulard, Westinghouse and more (with a description of what Tesla did and didn’t do in the evolution of electricity).

Hello, my name is Kathy Joseph and I have done a lot of original research from 1800s papers, magazines, patents, and books to tell you the shocking history and physics of AC transformers. Now Electric transformers are very simple devices: basically they are just two coils of wire wrapped around iron. However, these simple devices allow us to harness energy from far away power plants and electrify our world. And the story of how they work, how anyone thought of using coils for this purpose, and the effect of this device on the war of the currents is truly shocking both literally and figuratively. I’m not kidding! Ready? ! Let’s go!

So before I get to the AC electric transformer, I need to begin with where it came from, the DC battery powered transformer.

Part 1: The Shocking DC Transformer

I would like to start on August 29 of 1831, when my all time favorite scientist Michael Faraday hopefully titled his diary: “Experiments on the production of electricity from Magnetism.” See, Faraday knew from his friend Andre-Marie Ampere, that if he added current to a coil wrapped around a glass bar, the joint actions of what Ampere later called the “solenoid” made this coil act in a way that was, “perfectly similar to the action of a [bar] magnet.”[1]

Faraday also knew from a retired soldier and shoemaker with some fabulous mutton chops named William Sturgeon that wrapping a coil around an insulated iron bar made a very strong magnet, stronger than they could get from any bar magnet at the time! As current could make a magnet, Faraday was sure that a magnet could make current, but he wasn’t having much luck with bar magnets. That is why Faraday decided to try to use the magnetism from an iron ring to attempt to carry electricity from one coil  to another. What Faraday found when he tried it was that the iron didn’t carry anything.

However, what he did find was that when he first connected or disconnected a battery to the first coil, the separate second coil would cause a magnetic needle to twitch one way or the other, which is how Faraday knew that the second coil had current induced in it. After thinking about it for about a month, Faraday came up with the theory that this occurred because when he first connected the battery, the first coil went from not acting like a magnet to acting like a magnet, and when he disconnected the battery the first coil went from acting like a bar magnet to not being magnetic again. In other words, it was the changing magnetic field that induced electricity in the second coil.[2]

By October, 1831 Faraday came up with an experiment to validate his theory: he demonstrated that he didn’t even need an electromagnet – he could just move a bar magnet in or out of a coil of wire and still induce electricity.[3]

Faraday’s work was published in November of 1831 and was an international sensation. That was why a 27-year-old scientist in St. Petersburg named Emil Lenz read about it. Before this time, Lenz had had little interest in electricity. He mostly focused on climate and oceanic studies and had just published his memoirs about traveling around the world as a naturalist in his late teens and early 20s.[4] Then, in 1830 or so Lenz read Georg Ohm and learned about Ohm’s law and he started getting intrigued with electricity and, upon reading Faraday, Lenz was hooked. By November of 1832, Lenz wrote that he was sure there would be a flood of papers due to “the great interest which the latest discoveries of Faraday in the field of electro-magnetism must awaken in all the natural philosophers of Europe.”[5]

Lenz added that after he read about Faraday’s experiments: “I first proposed to myself to find out in what manner the phenomena of the magnetic action on a spiral suddenly approached or removed might be produced in the easiest and most powerful manner.”

Yes, Lenz wrote in an awkward way. Anyway, as you can tell Lenz wasn’t just interested in how much the compass twitched, but how much “power” the coil produced, which for Lenz was the same as what we call the induced voltage or “electromotive force, emf” of the wire. Now he could have measured that “power” or emf by using his body as a voltmeter, where the shock was equal to the current through him which is proportional to the potential difference or the spark it made. However, how shocked you are isn’t particularly mathematical and they had trouble creating a spark with a moving magnet because their bar magnets were very weak.

Instead, Lenz declared that the “power” was dependent on speed of the current which he stated was related to the square root of a trigonometric function called the “versine” of the angle.[6]  (I had to look up what a versine is, it is one minus the cosine!).

Anyway, Lenz then used the math conversion that one minus the cosine equals two times the sine squared of the half angle to get that the “power” induced in the coil depended on the sine of the half angle of the deviated compass (I know, crazy, but it works). He then found that if he used the same length of wire but coiled up between 5 and 30 loops or “convolutions” that “The electromotive power which the magnet produces in a spiral… is directly in the same proportion as the number of the convolutions.”[7]

In other words, more coils, more shocking voltage. When I was in school, I was taught that this equation is called Lenz’s law, but as I was editing this video I learned that sometimes only the negative sign is “lenz’s law” and the whole thing is called “Faraday’s Induction Law.” This drives me crazy, because 1) Lenz should get the credit and 2) Maxwell wrote what Heaviside called “Faraday’s law” as:

And although these two laws are mathematically equivalent, it seems very confusing to use the same name for two equations, so I will continue to call this “Lenz’s law,” and this “Faraday’s induction law,” I hope that is OK. Anyway, notice that both “Lenz’s law” and “Faraday’s induction law” have a negative sign, because, as Lenz noted in his wordy way in 1834, induction is a type of friction, it always works against the change in magnetic flux, or the magnetic field from the induced current would create a force on the magnet to change more, which would induce more current and then you could get infinite current

Of course, our friend Michael Faraday wasn’t done yet. A little over a year later, in January 1835, for Faraday’s 9th paper on electricity and magnetism in 4 years, logically if not poetically titled “The 9th Experimental Researches in Electricity” Faraday noted that a friend had found that if you wrapped a coil around an electromagnet (instead of around the other end of an iron ring) “a shock is felt each time the contact with the electromotor is broken.”[8] This is important, as Faraday had previously found how to induce current by the magnetic deflection, but now he knew how to determine how much voltage he had induced by the shock or later by the spark. This was better for Faraday as he had no math skills whatsoever, and he hadn’t read Lenz (or Ohm).

Meanwhile, William Sturgeon, the shoemaker with the fabulous facial hair who had discovered that iron makes a strong electromagnet 9 years earlier, was getting deeply frustrated with the institute where Faraday worked. It started to feel to Sturgeon that despite the fact that he had won an award for his electromagnet, the Royal Institute was only willing to publish work from a poor person with no background if that person’s name was Michael Faraday. By October, 1836, Sturgeon gave up and started his own magazine where he promised that “every description of new experiments or instruments in Electricity [or] Magnetism… will find a place in this work.”[9]  Soon, the articles came pouring in, including an article from an Irish priest named Nicholas Callan. Callan had read Faraday’s comment about getting shocks every time that the connection was broken and was inspired to build what he called an “electromagnetic repeater… devised for rapidly breaking and renewing communications with a voltaic battery.” Callan’s repeater consisted of a wheel where if a person spun it once a second it would create 3,600 shocks a minute which he was very pleased about.[10]

But that was not all, with his repeater to give basically constant shocks, Callan could manipulate the coils to improve the shock. This is how he found that when he “took shocks from wires of different lengths coiled on the same iron bar” he “always found that…the strongest shock was obtained from the longest wire.” This is how Callan experimentally determined that more loops induced more voltage just as Lenz discovered with mathematics and a moving magnet.[11]

Now Callan wasn’t the first to make a shocking repeater, heck he wasn’t even the first to publish a description of a repeater in that magazine,[12] but he was the first (as far as I can tell) to publish the description of a shocking machine which created higher voltage, which, in a way, made him the inventor of the step-up transformer. Anyway, these “shocking” devices were instantly popular for entertainment and medical devices and soon there was a running competition to make the biggest shock or spark possible.

By 1851, a 48-year-old German mechanic living in Paris named Heinrich Ruhmkorff invented a new method of winding these coils and managed to make a device that could make sparks that were an eighth of an inch long. Soon after that, Ruhmkorff was advised by a scientist named Hippolyte Fizeau that adding what Fizeau called a “condenser” (or what most physicists call a capacitor) to the circuit caused significantly greater sparks and shocks.[13] By 1864 Ruhmkorff’s devices were so powerful that he won a 50,000 franc prize from the Emperor Napoleon III for “The Most Important Discovery in the Application of Electricity,”[14]

Five years later in 1869 a German scientist named Herman von Helmholtz derived the mathematics of why adding that capacitor/condenser to the circuit had increased the efficiency of the Ruhmkorff coil and determined that the resistance, capacitor, inductor circuit created pulses of alternating current.[15]  Irrespective of how the Rhumkorff coil worked, they made big sparks and, therefore, they were very popular for scientists and for amateur doctors. Edison himself sold a version of a Ruhmkorff coil called an “inductorium” in 1874 for $6 as “a specific cure for rheumatism, and as an inexhaustible fount of amusement.”[16]  Which I find amusing.

Speaking of Edison, four years after he made a good profit on the amusing shocking machine, on September 8th, 1878, Edison visited an engineer named William Wallace who was demonstrating a direct current system to illuminate street lights called arc-lamps. According to the reporter who Edison invited to the event, “[Wallace’s demonstration] filled up Mr. Edison’s cup of joy.”[17] At first, Edison was only interested in electrical power for workers, but within a week of the visit Edison switched to focusing on electrical lights for homes and businesses and declared that, “he has discovered how to make electricity a cheap and predictable substitute for illuminating gas”[18] and that “with 15 or 20 of these dynamo-electric machines recently perfected by Mr. Wallace I can light the entire lower part of New York City” and that he would be demonstrating this marvel within “a few weeks.”

Of course it took more than a few weeks to demonstrate it and even longer to light New York City. In fact, it took until September 4 of 1882 almost four years to the day when he visited Wallace’s shop, for the first electric power station in the world to be built.

As Edison was initially interested in motors which at the time only worked with DC, he felt that there was no reason to use the inferior AC generators with his incandescent lamps, and, at the time there wasn’t. However, on September 13, 1882, just nine days after Edison’s electric power station was finally turned on, a Frenchman named Lucien Gaulard and his financial backer John Gibbs filed for a patent for something they called a “secondary generator”[19] which is now known as a transformer. In less than 4 years, Gaulard’s idea inspired the creation of a million dollar AC incandescent light bulb business and, soon after that, caused Edison to lose his mind.

Part 2: Electric Transformer for AC transmission

Now I am going to go back to… you guessed it Micheal Faraday! Back in January 1835, when Faraday mentioned how the transformer can shock you, he noted that the purpose of the paper was to study, what he said was “the influence by induction of an Electric current on itself.”[20]  Faraday’s conclusion was clear, “There can be no doubt that the current in one part of a wire can act by induction upon other parts of the same wire which is lateral to the first.”[21] 

Faraday even determined that if he induced current in a very long wire it would “remain cold but gave a bright spark on breaking contact” whereas if he induced current in the wire 12 inches long, it would “become very hot from the greater quantity of electricity passing through it, and yet the spark on breaking contact was scarcely visible.”[22]

Now the thing about Faraday is that he was beyond brilliant, but he couldn’t do any mathematics. That is why, beginning in 1855, a young Scottish scientist named James Clerk Maxwell decided to add mathematics to Faraday’s ideas,[23] including Faraday’s theory that maybe light was a vibration of electric and/or magnetic lines of force which is how Maxwell ended up with Maxwell’s equations!  I am not exaggerating how influenced and inspired Maxwell was by Faraday. For example, Maxwell wrote in the introduction to his 1873 electrodynamics book that, “If anything I have… written …may assist any student in understanding Faraday’s modes of thought and expression, I shall regard … the accomplishment [as] one of my principal aims — to communicate to others the same delight which I have found myself in reading Faraday’s Researches.”[24]

In his papers, Maxwell called the magnetic field the “magnetic induction” as it is what changes when you induce current in a wire. Then, in 1873, Maxwell wrote a book where he labeled this “magnetic induction” with the letter B (where the letter didn’t mean anything, it was just randomly chosen because he wanted to use all the letters from A-K for all his vectors).[25] It was also in his 1873 book Maxwell wrote a law for induction which in words was described as: “When the number of lines of magnetic induction which pass through the secondary circuit in the positive direction is altered, an electromotive force acts round the circuit, which is measured by the rate of decrease of the magnetic induction through the circuit.”[26] 

This statement actually explains why Lenz and Callan determined that more loops made more electromagnetic shock. If you increase the number of loops, you also increase “the number of lines of magnetic induction which pass through the secondary current,” by the same amount so you get more induced voltage. In other words, the change in magnetic field in the loop increases when you increase the size of the loop by adding more loops.

Maxwell also translated Faraday’s discoveries of “self-inductance” from his 9th paper into mathematical form.[27] What Maxwell put this in mathematical form which can be written as a modified Ohm’s law or what I like to call a “Ohm/Faraday induction law” :

V - L\frac{di}{dt}=iR

Where \frac{di}{dt} is the change in current over time and Maxwell called L the self-induction of the coil which depends on the physical properties of the coil. The reason Ohm’s law is modified is because if a current is changing then, by induction, the changing current creates a changing magnetic field which induces a “back voltage” which reduces the total current. 

You might notice that in this equation the induced voltage is the potential difference and given the letter V whereas in “Lenz’s law” the induced voltage is called the emf and given the Greek letter epsilon. Let me explain. First, for a DC battery, these two things are different. The emf is the potential of the battery without any current, or electrical load. A 9 volt battery has 9 volts of emf. However, if you have current in a battery, then due to internal resistance the actual potential difference is smaller with the equation:

V =\varepsilon - ir

When it comes to induced voltage in a coil, however, it gets confusing. In truth, it doesn’t make sense to talk about emf as you can’t get induced voltage without current, but, due to the history, we still use it but only in equations to determine the induced voltage due to the external magnetic fields (like Lenz’s law) and then we use the term potential difference or induced voltage with the letter V in equations where you determine the relationship between the potential and the current in the wire, like the “Ohm/Faraday Induction law.” 

Anyway, you can see from this “Ohm/Faraday induction law” equation that if current changes then the current is always smaller than expected from Ohm’s law. For alternating current, the current is always changing, so the total current is always less than expected from Ohm’s law. Note that even straight wires have self-inductance, but they tend to be small and this effect is usually ignored or folded into increasing the resistance of the wire. 

Coils of wire, on the other hand, have significantly greater values for L as the magnetic field from one wire affects the current in the opposing wires. In fact, the self-inductance of a solenoid if you ignore the self-inductance due to the thickness of the coils and the edge effects is related to the number of coils squared. [28] That is why, although the voltage increases linearly with the number of coils, even in an ideal situation with no resistance and no hysteresis in the magnet, the current decreases by the number of coils. In real world situations, the current is even smaller than that. That is why a transformer with more coils both induces more voltage and less total current.  

One more comment about transformers and power and energy. Like I said, due to self-inductance, alternating current is always less than what you would expect from Ohm’s law. That also means that Joule’s and Lenz’s power law ( P=i^2R ) tells you how much power is lost to heat in the wire, not the total power of the coil which is P=i(V - L\frac{di}{dt}). However, if you combine these laws, you get P=iV , and that works every time. That is also why most transformers are rated for kVolt-Amps, as that is the power of the transformer. 

Now Power is the derivative of the energy over time, so the average energy is the power times the time. That is why if the number of coils increases, the amount of current must decrease by that amount or more or you will get more energy than you began with.

In fact, any amount of electromagnetic waves or pulses from the current in the wire must reduce the current, and the energy, in the same section of wire. If it didn’t, then not only could you have a perpetual motion machine, you would also have a perpetual motion machine that keeps on accelerating. [Although an electromagnetic wave or pulse can transmit the electricity from one wire to another, which is how the transformer works] In other words, the energy is sometimes in the wire and sometimes in the electromagnetic wave and sometimes even in dielectrics, depending on the circuit and where you are in the circuit. That is how energy works, it transfers from one type to another and one form to another but you can’t get rid of it. That is the first law of thermodynamics.

Now we get to 1882 and Lucien Gaulard the inventor of the transformer. Gaulard did not leave a lot of clues that I could find as to what influenced him to change the Ruhmkorff induction coil into a method of AC transmission, but here is my best guess.

I don’t think Gaulard read Maxwell as most people found his book to be impossible to read but, on the other hand, there is no doubt in my mind that Gaulard had read Faraday’s Researches in Electricity – every electrician at the time had read Faraday’s collection of his 29 papers on electricity especially as it contains no math. If you want to see how influential Faraday was with early electrical engineers, just look at a few of the terms that Faraday coined (sometimes by consulting a linguist) that electrical engineers still use in the way Faraday intended: magneto-electric induction,[29] anions, anode, cathode, cations, electrolyte, electrolyzed, ions,[30] dielectric,[31] magnetic field,[32] diamagnetic, paramagnetic,[33] and ferromagnetic.[34] and I am sure I am missing a lot.    

Anyway, my guess is that Gaulard could see that the Ruhmkorff coil could produce a terrific spark, and therefore, according to Faraday, would produce less current and less heat in the wire. Gaulard also realized that the Ruhmkorff coil had a lot of complicated parts but most of the materials in it, the automatic magnetic switch and the capacitor or the condenser and often other doodads, were just there to make the direct current from the battery produce pulses of alternating current. Gaulard realized that with current from an AC generator, you don’t need all of that, the current is already constantly alternating. All you need is two separate coils of different lengths wrapped around an iron bar. Then, if you put alternating current in one coil, a different alternating current and voltage would pop out the other coil.

Gaulard then had a vision: generate the electricity at high voltage to the ground and low current far out of town where one could be loud and make fumes or where one could build a hydroelectric dam. Transmit the electricity high up in the air in isolated areas so that the dangerous electric potentials wouldn’t be a problem and the low currents would cause the heat loss to be minimal. Then, near a city or town use the Ruhmkoff coils backwards as what he called a “secondary generator” to transform the electric potential down to a safe level.[35] The current will go up when you do this, of course, which increases the heat of transmission, but it didn’t have as far to go by then. As he put it his device made it “possible to carry a large amount of electrical energy on a small conductor, and to draw it off at various points…under such conditions as are required” where “the means by which this is effected recalls the Ruhmkorff coil, consisting as it does of two distinct coils and an iron core… the first, which is traversed by an alternating current, induces or generates a current in the second at every pulsation of the current. There is no mechanical movement whatever, the motion being entirely molecular”[36]

Although Gaulard said he was inspired by the two coils in a Rhumkorff coil, his device didn’t look anything like it. And that is because of something called eddy currents. See, if you have a changing magnetic field near iron it will induce currents to swirl around in the iron too. Those currents don’t do anything useful, they just make a lot of heat. That is why the iron in a Rhumkorff coil was not a solid iron bar but a bunch of laminated iron chords put together, an idea that came from William Sturgeon of the fabulous sideburns. However, Gaulard found that most of the eddy currents were down the iron not across the iron, which is why his device looked like stacked plates. At first, everyone ridiculed Gaulard’s idea but they started to change their tunes in September 1884 when he won 10,000 francs for demonstrating his device for transmitting electricity 25 miles away and back![37] 

Quickly, a trio of Hungarian engineers named Zipernowski, Blathy and Deri (nicknamed the ZBD group) made a far more practical transformer and electrical system in parallel instead of in series as well as the name transformer (although even they admitted that “Gaulard and Gibbs are undoubtedly to be credited with first having proved the practical applicability of secondary generators.”)[38]

You might wonder why so few people have heard of Gaulard and the answer is tragic. Truly tragic. After Gaulard and Gibbs won the 1884 prize they were hired to use their system to light a Gallery in England and an Englishman named Sebastian Ferranti was hired to run it. By December 1885, Ferranti filed for a patent that was, according to Gaulard’s lawyer “identical” to Gaulard’s except in parallel. When Gaulard and Gibbs sued for patent infringement, Ferranti countersued them to revoke their patent for not being “novel” as everyone knew about Rhumkorff coils.[39] As the court case heated up, Gaulard had a mental breakdown. In February of 1888, less than 6 years after his first patent he was found on the streets declaring himself a “God” and demanding to see the president as “God does not wait.” He was taken away to an asylum and as the newspaper sadly noted, “The unfortunate man, who is afflicted with lunacy and general paralysis is no other than M. Lucien Gaulard of secondary generator fame.”[40]

A few months later, in July, Gaulard’s financial backer, Willard Gibbs, tried his best to defend themselves in court. However after Ferranti’s star witness Sir. William Thomson aka. Lord Kelvin (who had helped Maxwell write his book) testified that, “it was perfectly known in 1882 how to construct the coil so that the current might be of an required quantity and tension in the secondary,”[41] Gaulard and Gibbs lost the case. The editor of the Electrical Review then wrote an article about why “Gaulard and Gibbs out certainly to have full credit for the invention of alternating transformer distribution” and how he felt sorry for them that they “cannot hold their patent, especially after the pluck and determination they showed when everybody, ourselves included, ridiculed their scheme.”[42]

Poor Gaulard died in the asylum in November of that same year[43] and Gibbs went bankrupt trying unsuccessfully to win in court. But Gaulard’s idea was to take root. As just as Ferranti was copying Gaulard’s idea, in December of 1885, a 39-year-old man named George Westinghouse Jr got his hands on Gaulard’s device. Which brings us to:

Part 3: Transformers and the War of the Currents

Westinghouse had made his fortune and multiple companies around his brilliant inventions for safety devices for trains. In fact, Westinghouse’s initial interest in electricity was to electrify the train signals to make them safer, but when he heard about Gaulard’s system in 1885, he was immediately inspired towards AC for incandescent lights. When Westinghouse finally got to see the “secondary generator” in person, he immediately realized that Gaulard’s design wasn’t practical for industry. According to a former Gaulard employee who was hired to deliver and explain the device, “Mr. Westinghouse applied himself toward the production of a piece of apparatus which could be wound on the lathe…[and] it took Mr. Westinghouse only a few days to design an apparatus which has been the standard ever since.”[44]

 By January 1886, Westinghouse was so excited, that even before he had a working AC system, he formed an incandescent light company just in case,[45] and by  March 20th, 1886, they had perfected the AC transformer enough for Westinghouse to ask an employee named William Stanley to secretly try out AC transformers for incandescent lamps in an out of the way town where no one would hear about it if it failed.[46] Then, as soon as Westinghouse finalized the purchase of Gaulards patent in May 1886, he filed for an “induction coil” patent[47] which, for the first time, used coils wrapped around layers of soft iron with insulated gaps in them to reduce the amount of eddy currents and was designed for simple manufacture. By late November or early December of 1886, Westinghouse’s Electric Company announced that “the Gaulard and Gibbs system of electric distribution… has been adopted by the Westinghouse Electric Company, of Pittsburgh, who propose to put it in active operation in this country.”[48]

Gaulard came up with the idea of transformers, the ZBD group improved it, but Westinghouse was the guy who invented and patented the modern single-phase AC transformer (and I know it was Westinghouse and not one of his employees as Westinghouse let all his employees file for patents under their own names while working for him).

Speaking of which, four months after Westinghouse filed for a patent for his “induction coil” or transformer, William Stanley patented his own electric transformer,[49] which gave people the false impression that Stanley, not Westinghouse, modernized the transformer, especially as Westinghouse was shy and Stanley was not, so many people believed Stanley as they were friends with him. That is why there is an IEEE plaque about how “William Stanley …demonstrated the first practical system for proving electrical illumination using alternating current with transformers to adjust voltage levels of the distribution system,” that doesn’t even mention Westinghouse’s name let alone his input.[50] We have this false history because Stanley actively promoted it even after Westinghouse successfully sued him. Stanley even went as far as to pretend that he was the one who conceived of and promoted the use of AC for incandescent lights. A Westinghouse employee named Panteolini, who was the person hired by Westinghouse way back in 1885 to “investigated and reported on the Gaulard and Gibbs alternating current system” recalled that “the opposition by ALL the electric part of the Westinghouse organization was such that it was only Mr. George Westinghouse’s personal will that put it through.”[51] If you look at this photograph of a “Stanley transformer” used in some of the first AC transmissions from the Ford museum, one can tell that Westinghouse’s former employees remembered correctly as it is clearly Westinghouse’s design not Stanley’s. It even has the same wood platform holding it up!

Anyway, Stanley’s transformer patent was not practical but it was so clear as to how they worked that within a few weeks Edison realized what Westinghouse was up to and he freaked out. By November, 1886, Edison was writing in his notebook that “Just as certain as death Westinghouse will kill a customer within six months of installing a system of any size.”[52] By December 1887, after the price of copper went sky-high Edison completely let into fear and paranoia. He had resisted all entrees to make money in weapons or war, was strongly against the death penalty, but he was so upset that he wrote that if we had to have a death penalty that: “the most effective [killing machines] are known as ‘Alternating Machines,’ manufactured principally in this country by Mr. George Westinghouse, Pittsburg.”[53]

After that, Edison started to publish articles and even a book about how deadly AC was and soon there was an AC panic. By June 1888, Westinghouse tried to smooth things over with Edison writing to him that, “I believe that there has been a systematic attempt on the part of some people to do a great deal of mischief … between the Edison Company and The Westinghouse Electric Company.”[54] But Edison was not convinced. Instead, unknown to Westinghouse, Edison started to collaborate with a man named Harold Brown, inviting Brown to his laboratory to prove the deadliness of AC on animals. Edison even ironically sent a letter to the local SPCA (Society for the Prevention of Cruelty to Animals) asking for some “good-sized animals” so that they could publicly electrocute them to “safeguard the lives of men engaged in electric lighting business.”[55]

It was only after this, in December of 1888, that Westinghouse bought Nikola Tesla’s patent for a 2-phase motor (which used 2 sets of AC wires) as well as 3-phase and 4-phase for $5,000 in cash, 200 stocks with a further unspecified amount per horsepower of motors produced.[56] You might think that Westinghouse underpaid for Tesla’s patent but Tesla couldn’t get the Tesla motor to work well enough to sell. In April of 1890 an Edison spy wrote that: “Mr. Westinghouse has ..[only] one alternating current experiment, which is a failure, and Mr. Westinghouse has quarreled with Mr. Tesla [misspelled Mr. Tessler] who invented the alternate current motor.”[57]

So if Tesla’s motor was a failure, how did it affect the electrical world? That brings me to:

Part 4: Nikola Tesla’s Surprising Influence

There is an autobiography written in 1926 by a former employee of Westinghouse’s named Benjamin Lamme which makes some truly astonishing statements about Tesla and his motor, which I think are worth looking at in some depth. According to Lamme, Westinghouse actually gave up on having an AC motor just after this letter was written in 1890. Lamme then claims that in early 1891 he told Westinghouse that he could improve the windings and get Tesla’s 2-phase up to snuff, but Westinghouse was burnt out on the whole issue and wouldn’t let him.[58] Then, according to Lamme. Westinghouse changed his mind in late 1891, the same year that Tesla demonstrated the Tesla coil, and finally let Lamme try to improve it and Lamme said he succeeded in late 1892 or early 1893 to create, “the first induction motor built by the Westinghouse company which bears any close resemblance to the modern type.”[59] 

But that is not all, Lamme said that once he improved Tesla’s motor they had a meeting to determine how they could get people to buy 2-phase generators so that they could use the 2-phase Tesla motors where Lamme suggested that Westinghouse paste “Tesla polyphase” on everything so that they could make a “fad” out of Tesla’s 2-phase generators. Lamme also suggested that they “get out a standard line of polyphase generators and push them on any and every occasion” “so that everybody would buy them.”[60]

Now you probably don’t believe Lamme. I mean, that is an outrageous statement.  Lamme is saying that Nikola Tesla’s induction motor took years to perfect and that he, not Tesla, made the final product and they only promoted Tesla’s name to help with sales. Take a moment. Process, because it was true and it wasn’t a secret everyone knew that it took years for Tesla’s motor to be perfected for industry. There are literally dozens of comments from contemporaries on the subject. when the IEEE gave Westinghouse their highest award, the “Edison Medal” in 1912 Elihu Thomson, that it “is well known to all” that Westinghouse “became one of the foremost exponents of the alternating-current system of distribution by transformers in spite of considerable opposition…[which was] two or three years later…strengthened by the acquisition of patents of Tesla in the polyphase field [although] it took years of skill and able engineers to render available in industry the induction motor.”[61] Even Tesla superfans like Bernard Behrend mentioned it. Now Behrend was so enamored of Tesla’s polyphase that he hosted Tesla’s Edison Medal award ceremony in December 1916 by saying that, “Not since the appearance of Faraday’s experimental researches in electricity has a great experimental truth been voiced so simply and so clearly as this description of Mr. Tesla’s great discovery of the generation and utilization of polyphase alternating currents. He left nothing to be done for those who followed him.”[62]

Anyway, despite this outrageous statement Behrend not only knew about and mentioned Lamme’s work on Tesla’s motor, he thought it was wonderful and actually hosted Benjamin Lamme’s award ceremony two years later for “his work in the transformation of Nikola Tesla’s great creative ideas into commercial form.”[63]

But why? Why would people like Elihu Thomson and Berhrand say so many great things about Tesla’s “polyphase” when he had nothing to do with the development or the implementation of the AC transformer and he didn’t even make the first industrial AC motor? There is a different answer for the different men. For Thomson, he had lived through the birth of our electrical age. He knew, and we forgot, that if you want to harness the power of Niagara and use it to power up industry in New York City, over 400 miles away, as Edison originally envisioned in 1878,[64] then you need more than a powerful DC generator, powerful DC motors and cheap electric light bulbs because before the invention of semiconductor diodes, they didn’t have a simple way to transform the electricity so they couldn’t transmit the electrical energy that far without losing too much energy to heat. You also need more than an electric transformer as that only gets you electric light from far away. In order to truly make an electrical world with power, you need AC transformers and powerful AC motors, and for that you need to use more than one phase of AC electricity.

Thomson knew that the reason that people started studying using more than one phase of AC electricity is because Nikola Tesla was awarded multiple patents for 2-phase and 3-phase generators and motors in late 1887 and early 1888 and convinced Westinghouse to purchase it in December of 1888. Others perfected Tesla’s idea: Michael Dolivo-Dobrovolski implemented 3-phase transmission and motors in 1891, Benjamin Lamme perfected Tesla’s 2-phase motor in late 1892 or early 1893 and made “Tesla’s polyphase” into a popular thing for the public, Charles Proteus Steinmetz created a math trick called phasors later in 1893 to help the Edison-free GE install 3-phase throughout the world. But it is possible that none of that would have happened if Tesla had not insisted that his 2-phase (and 3-phase) motors were perfect and convinced a smart man like Westinghouse to put cash into it. Tesla believed that polyphase could make Edison’s initial dream of an electrical world a reality and he was right. It is hard to not look at Tesla’s patents and find them beautiful, they really showed a new way of using electricity that we continue to use to this day.

However, at the time, no one thought of Tesla having anything to do with the development of single-phase AC transformers. Then, in 1895 Westinghouse sued GE (who was using 3-phase) and Stanley (who was using 2-phase) for using “Tesla polyphase.” That is when Westinghouse took out full page ads that stated that Tesla’s system was “especially adapted to transmission of power over great distances”[65] which is technically true but they could transmit light over long distances before polyphase. This wording, however, helped convince the general public and many electrical engineers that Westinghouse’s entire company, and AC transformers were due to Tesla’s patents.

Anyway, that is why people like Behrand (who was 13 years old in 1888) thought that Tesla had not only patented 2 and 3 phase but also the electric transformer which is why Behram said, “Were we to seize and to eliminate from our industrial world the results of Mr. Tesla’s work, the wheels of industry would cease to turn, our electric cars and trains would stop, our towns would be dark, our mills would be dead and idle. Yea, so far-reaching is this work that it has become the warp and woof of industry.“ [66]

As the years passed Tesla started to believe his own hype. Then, after Henry Ford had a giant party for the 50th anniversary of Edison’s patenting his first light bulb, the papers were filled with accolades for Edison without mentioning Tesla,[67] and the 73-year-old Tesla claimed that he, not Westinghouse, was Edison’s rival during the war of the currents, writing that, “Edison and his associates bitterly opposed the introduction of my system, raising a clamor against the ‘deadliness’ of the alternating current.”[68]

This was the origin of the Edison/Tesla “rivalry” before that date, neither Tesla nor Edison had ever mentioned any rivalry over the war. In fact, when a magazine tried to manufacture a rivalry in 1896,[69] Edison wrote a private note chastising the editor as “Tesla is of a nervous temperament and it will greatly grieve him and interfere with his work.” [70] and Tesla said multiple times that meeting Edison was “extraordinary” and that, “When I saw this wonderful man.. and saw the great results by virtue of his industry and application, I felt mortified that I had squandered my life.”[71]

Anyway, once Tesla had convinced himself that he and Edison were rivals, his stories became even more outrageous. By the end of his life he ended up telling his biographer some truly wild tales, which ended up with the Tesla myth that has continued to this day. For example, in the book “Prodigal Genius” Tesla told the author that he dreamed up the idea for polyphase motors and generators while reading poetry in February of 1882, and within two months, working out the “design of dynamos, motors, transformers and all other devices for a complete alternating-current system.”[72] Mind you, with these dates Tesla is saying that he thought of polyphase transformers 5 months before Lucien Gaulard filed for a patent for his “secondary generator,” for single phase AC.[73] Of course Tesla didn’t mention Gaulard’s, or the ZBD group’s or Westinghouse’s or anyone else’s involvement in the AC single phase transformers. Instead, his biographer was convinced that it was, “Tesla’s alternating-current power system…that freed electricity from its bondage to local isolation… by a highly efficient method of using transformers which consisted of two coils of wire around an iron core”[74]

Tesla said that he quarreled with Edison about AC in 1884, but Edison only heard about transformers with the ZBD group in 1885 and only started to worry about AC in November of 1886 after Stanley published his patent for a simplistic transformer.

Tesla also said that as soon as Westinghouse heard about his system in 1888 he offered a “startled Tesla” a million dollars cash on the spot.[75] When the truth is that Westinghouse paid him $5,000 cash in two installments after negotiating.

Tesla also insisted that Westinghouse visited Tesla after the war of the currents was over to tell Tesla that his “polyphase system” was “the greatest discovery in the field of electricity” and that it was Westinghouse’s “efforts to give it to the world” that were the reason that Westinghouse created his “original plans to put the country on an alternating current basis.”[76] This can be simply denied by the fact that Westinghouse published that he was installing Gaulard’s AC transformer in December of 1886 and only purchased Tesla’s patent in late 1888. Which… how did people miss that one? Anyway, Tesla also said that in this same conversation Westinghouse convinced Tesla to donate his royalties to Westinghouse worth 12 million dollars and which “resulted in one of the greatest handicaps to scientific and industrial progress which the human race has experienced.”[77]

This was completely made up. The truth is that in April 1896 Westinghouse dropped his lawsuit with GE over Tesla’s polyphase and instead got into a patent sharing deal where Westinghouse gave a lump sum of $216,600 to Tesla “in order that both companies might manufacture apparatus covered by those patents without the payment of royalties.”[78]

This last one is particularly cruel to poor Westinghouse’s reputation as now everyone thinks that Westinghouse was just a greedy money man who destroyed our Tesla-based utopia when, in reality, Westinghouse was brilliant and everyone talked about how kind and generous he was to both his engineers and his regular employees. That is why in 1900 44-year-old Nikola Tesla said, “[Westinghouse] is one of those few men who conscientiously respect intellectual property, and who acquire their rights to use inventions by fair and equitable means… Had other industrial firms and manufacturers been as just and liberal as Mr. Westinghouse, I would have had many more of my inventions in use than I now have.”[79]

In fact, Westinghouse was so good to his employees that the founder of America’s biggest union said, “I will say this for George Westinghouse. If all employers of men treated their employees with the same consideration he does, the American Federation of Labor would have to go out of existence.”[80] 

I feel like the Tesla myth in particular is damaging to science understanding and development. Instead of science being a river of ideas inspired and debated by a range of people, everything comes straight from the brain of one man, “like Minerva emerging fully armed from the head of Jupiter” as Marie Sklodoska Curie used to say. 

If you read Tesla’s biography you will read that, “Even the gods of old, in the wildest imaginings of their worshipers, never undertook such gigantic tasks of world-wide dimension as those which Tesla attempted and accomplished. On the basis of his hopes, his dreams, and his achievements he rated the status of the Olympian gods, and the Greeks would have so enshrined him.”[81] And it is because Nikola Tesla, like Gaulard before him, ended up telling everyone he was God. The only difference is, a lot of people believed Tesla, and believe him still.

Despite this, these stories have been repeated in endless books and documentaries verbatim even though, as I hope I have demonstrated, it is not true.

This version of history denies not only the influence of Westinghouse on the AC transformer but also of the ZBD group, Gaulard, Maxwell, Helmholtz, Fizeau, Ruhmkorff, Callan, Lenz, Sturgeon, Ampere,  and Faraday and more.

The minimization of Faraday’s influence is particularly galling to me as he was, without using any mathematics, the inspiration of not just the AC transformer and the induction coil, but also the generator, Electric and Magnetic fields, the electromagnetic view of light, Maxwell’s equations, radio, E=mc^2, the discovery of the electron, X-rays, radium, the nucleus, quantum mechanics and more! Faraday was venerated in his life but he remained humble, refusing to be knighted by Queen Victoria, and lived a simple life of service to knowledge. I happen to think that he was the GOAT: greatest of all time, and I am not alone in this. In 1931 Ernest Rutherford, who was pretty inspiring himself said: “There is no honor too great to pay to the memory of  Micheal Faraday, one of the greatest scientific discoverers of all time.”[82]

It might sound like I am doing the same thing for Faraday as Behrend was doing for Tesla, and it is true that I am a Faraday super-fan.  But there is, I think, a significant difference. Unlike Behrend I don’t think Faraday’s discoveries were complete and that  “he left nothing to be done for those who followed him.”[83] Instead, Faraday’s and Tesla’s main accomplishments were in how much they left for those that followed them, not for how little.

You might have noticed that I have told a lot of stories that I am pretty sure  you haven’t seen anywhere else. And that is because I don’t make videos from information I get from a website or a book. Well, that isn’t technically correct. I started with the information on Wikipedia or sometimes a book, usually from the early 1900s, to get dates and names and quotes and then I looked for the patents, original papers and newspapers and magazines articles. For example, I looked up Lucien Gaulard’s wikipedia page and it said that “Gaulard died in an institution (Sainte-Anne Hospital) in Paris” so I searched for Gaulard and “Sainte-Anne” in Google books and bob’s your uncle, I found the original death notice for him in French! And I do that for everything. Why? Well, I believe that the best way to explain physics and technology is through the history of the scientists and engineers who discovered it in the first place. And that doesn’t work if the history is fake. So I validate everything. Everything. And that is why I make a lot of new discoveries in history which was not my original goal but is important I think.

If you want to see the original sources for yourself, I tried to make it as easy as possible. I put the script for this video on my website and I not only put a lot of footnotes but also made them linked so all you have to do is click on the link and then you can go right to it, no researching the web required. If you happen to know how to edit Wikipedia I would love it if after you have triple checked my work you would try to fix some of the misconceptions in history on there. For example, poor Gaulard’s site could really use the help. And you don’t have to include me. I am not the person who discovered that one could use a Rhumkorff coil backwards to allow us to transmit AC electricity long distances, Gaulard was. I wasn’t even the one who discovered that Gaulard did this, I mean, they tried to erect a statue to the man in 1890, it is all publicly available, we just forgot. 

Also, when you find places where you think I have made mistakes or misrepresented things, please don’t just tell me, tell other people! Write an article, a blog, Facebook, reddit, youtube video whatever is your long form mode of communication and tell people what you think I got wrong and why (making sure to include citations to original documents). And then other people will argue with you and then we can start a dialogue. I tried my best to be as accurate as possible but I am just 1 person and it is silly to just rely on me and my work. In fact, I think it is silly to rely on any one person and their work. Why not work collectively to try to understand our world and our history?  That is how science develops, why can’t that be how science understanding develops too?

Anyway, I have a ridiculous number of videos on all sorts of subjects including on how the Tesla myth became ubiquitous, the evolution of 2-phase and 3-phase and the life of Edison and Westinghouse and two on the work of Charles Proteus Steinmetz but I haven’t said how, on a fundamental level phasors work and why Steinmetz has accidentally convinced us that Ohm’s law works for circuits with changing current when it doesn’t. So that is next time on the evolution of wireless. I also have a book called “The Lightning Tamers” which covers how electricity got in our homes through the story of the scientists and tinkerers who lived between 1580 and today, also with a ridiculous number of citations, which inspired this channel if you want to read about it too.  

[1] “Suite du Mémoire sur l’Action mutuelle“ Annales de Chimie et de Physique vol 15 (1820) p. 208-9 also A. K. T. Assis and J. P. M. C. Chaib, Ampère’s Electrodynamics (Berlin: Apeiron, 2015), p. 82

[2] Michael Faraday,“Experimental Researches in Electricity” (Nov 24, 1831) Proceedings Royal Society vol. 122 p. 149

[3] Paragraph 57, October 17, 1831 according to Silvanous Thompson Michael Faraday; His life and Work (1898) p. 112

[4] According to Stine The Contributions of Lenz to Electromagnetism (1923) p. 66 and 152  The Contributions of H.F.E. Lenz to Electromagnetism – Google Books

[5] Lenz paper

[6] Lenz “On the Laws according to which the Magnet acts upon a Spiral” (November, 1832) from Richard Taylor selected from the transactions of foreign Academies of Science (1837) p. 612-13

[7] Lenz p. 616

[8] Faraday “9th Series” (Jan 29, 1835) paragraph 1049 p. 322

[9] Sturgeon “Prospectus” p. ii The Annals of Electricity Magnetism and Chemistry and Guardian of Experimen… – Google Books

[10] Callan p. 229-230 Annals of Electricity, Magnetism, and Chemistry – Google Books

[11] Callan p. 296-7 Annals of Electricity, Magnetism, and Chemistry – Google Books

[12] See Charles Barker “To The Editor” p. 157-58 and figures 38- 41 on plate 6 approx pg. 519 Annals of Electricity, Magnetism, and Chemistry – Google Books

[13] “Heinrich Daniel Ruhmkorff” p. 13

[14] According to Jean Dumas “Scientific Worthies”(Feb 6, 1880) Nature vol. 20 p. xxxi

[15] p. 268

[16] [D7408D], Publication, Edison and Murray, 1874

[17] “Inventions Big Triumph” The New York Sun (Sept 10, 1878) Old Fulton NY Post Cards By Tom Tryniski ( Easier to read: Thomas Edison Papers Digital Edition (

[18] “Edison’s Newest Marvel” (Sept 16, 1878)  Thomas Edison Papers Digital Edition (

[19] “The National Company for Distribution of electricity v. Gibbs” (April, 1899) Reports of Patent, Design and Trademark Cases vol. 16 (1899) p. 339 Reports of Patent, Design, and Trade Mark Cases – Google Books

[20] Faraday “9th Series” (Jan 29, 1835) paragraph 1049 p. 322

[21] p. 339 Experimental researches in electricity : Faraday, Michael, 1791-1867 : Free Download, Borrow, and Streaming : Internet Archive

[22] Faraday “9th Series” (Jan 29, 1835) paragraph 1049 p. 326

[23] Maxwell “On Faraday’s lines of Force” (Dec, 1855) The Scientific Papers of James Clerk Maxwell vol. 1 (1890) p. 155

[24] Maxwell on Faraday in book intro p. xiv

[25]  Maxwell p. 236-7

[26] Maxwell on Lenz’s law

[27] Maxwell on Faraday’s 9th paper p. 179

[28] Maxwell p. 281

[29] Faraday #1

[30] Faraday “Experimental Researches #7” (1834) p. 196-8 Experimental Researches in Electricity vol 1 (1839)

[31] Faraday #15

[32] Faraday #20

[33] Faraday #25


[35] Gaulard and Gibbs patent “System of Electric Distribution” (Oct, 1886)

[36] p. 458

[37] “The Turin Installation” p. 19-20 The Distribution of Electrical Energy by the Gaulard-Gibbs System of Second… – Google Books

[38] “Secondary Generators of Transformers” (October 10, 1885) The Telegraphic Journal and Electrical Review vol. 17  p. 324

[39] vs. Ferranti p. 48  The Electrical Review – Google Books

[40] “A Sad Case” The Telegraphic Journal and Electrical Review (Feb 24, 1888) p. 201 Telegraphic Journal and Electrical Review – Google Books

[41] vs. Ferranti p. 48  The Electrical Review – Google Books

[42] “The Gaulard and Gibbs Case” The Telegraphic Journal and Electrical Review vol, 23 (July 13, 1888) p. 30 The Electrical Review – Google Books

[43] p. 470 International Review of Electricity and Applications – Google Books

[44] Belfield quoted in George Westinghouse Commemoration (1937) p. 23 George Westinghouse Commemoration : The American Society Of Mechanical Engineers New York : Free Download, Borrow, and Streaming : Internet Archive

[45] p. 76 Official Documents, Comprising the Department and Other Reports – Google Books

[46] IEEE Berkshire Section – Forms and Files

[47] Westinghouse “Induction Coil” Patent US342553 (May 5, 1886) US342553A – Induction-coil – Google Patents

[48] Dec 4, 1886 p.271 Electrical World – Google Books

[49] US349611A – Signoe to geoege westing house – Google Patents

[50] IEEE Berkshire Section – Forms and Files

[51] Harold Passer “The Inventor-Businessmen: Westinghouse and Edison” p. 95 The Robber Barons Revisited (Magazine) (1968) the robber barons revisited : Free Download, Borrow, and Streaming : Internet Archive [Note: Harold Passer’s book on this subject is out of print but is quoted extensively by many – this article is a fascinating read and free on the internet with a library pass.]

[52]  “[X710A] Thomas Edison to Edward Johnson,” The Thomas A. Edison Papers, November 1886. p. 15

[53] [LB026116] Edison to Soouthwick (Dec 19, 1887)

[54] Westinghouse to Edison (June 7, 1888)

[55] [LB026273] “Thomas Edison to Henry Bergh,” The Thomas A. Edison Papers, (July 13, 1888)

[56] Billingsly (Westinghouse VP) to Nikola Tesla (Dec 13, 1888) found in Jeff Behary Agreement Between Tesla and Westinghouse (2022)

Agreement between Tesla and Westinghouse : Jeff Behary : Free Download, Borrow, and Streaming : Internet Archive

[57] Frank Sprague to Sprague Executive Board (leaked to Edison) (April 29, 1890) Edison Papers Digital Edition [X120CBN]

[58] Lamme “Story of the Induction Motor” (March, 1921) Journal of AIEE vol. 40 p. 207 Journal of the American Institute of Electrical Engineers – Google Books

[59] Lamme, Benjamin Garver Lamme, Electrical Engineer, An Autobiography, (1926) p. 61

[60] Lamme “Story of the Induction Motor” (March, 1921) Journal of AIEE vol. 40 p. 207 Journal of the American Institute of Electrical Engineers – Google Books

[61] “Acknowledgment of the Award,” Electrical Engineering 31 (1912): p. 332

[62] (May 5, 1917) Electrical Review and Western Electrician vol. 70 no. 21 p. 880

[63] Behrand “The Achievements of Benjamin G. Lamme” p. 236 The Electric Journal vol. 16 (1919) The Electric Journal – Google Books

[64] “Edison’s Newest Marvel” (Sept 16, 1878)  Thomas Edison Papers Digital Edition (

[65] “Notice: Westinghouse Electric” (April 17, 1895) Electricity vol 8, No. 14 p. 199 (marked iv) Electricity – Google Books

[66] (May 5, 1917) Electrical Review and Western Electrician vol. 70 no. 21 p. 880

[67] Detroit Free Press Front Page,” World’s Tribute to Edison Voiced by Hoover,” 1929 – The Henry Ford

[68] “Mr. Tesla Speaks Out,” New York World, November 29, 1929.

[69] “Edison and Tesla Rivals” New York Journal, May 22, 1896.

[70] [LB062498], Letter from Thomas Alva Edison to Electrical Review (N.Y. City), May 29th, 1896 default.jpg (855×1073) (

[71] Tesla “Mr. Tesla’s Address of Acceptance” Electrical Review and Western Electrician vol. 70 no. 21 p. 882

[72] John Joseph O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 48-50

[73] “The National Company for Distribution of electricity v. Gibbs” (April, 1899) Reports of Patent, Design and Trademark Cases vol. 16 (1899) p. 339 Reports of Patent, Design, and Trade Mark Cases – Google Books

[74] O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 71

[75] O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 74-5

[76]  O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 82

[77]  O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 82

[78] “Annual Report of the Board of Directors of the Westinghouse Electric” Electricity vol 12(June 1897): 387.

[79] Tesla “Tesla’s Tribute to Westinghouse” The Age of Steel (Sept 8, 1900) No. 10, vol. 88 p. 9

[80] “George Westinghouse Commemoration,” American Society of Mechanical Engineers (1937), 49. George Westinghouse Commemoration : The American Society Of Mechanical Engineers New York : Free Download, Borrow, and Streaming : Internet Archive

[81] John Joseph O’Neill, Prodigal Genius: The Life of Nikola Tesla (1944), p. 3 & 7

[82] This was originally in p. 39 Notices of the Proceedings – Google Books  but it is now in snippet view 🙁 if you want the full quote please see: p. 55 The Age of Synthesis – Google Books

[83] (May 5, 1917) Electrical Review and Western Electrician vol. 70 no. 21 p. 880

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