The Niagara Falls are located on the border of Ontario, Canada and New York, USA.
The Niagara Falls are made up of 3 waterfalls, the American Falls, the Bridal Veil Falls and the Horseshoe Falls.
The Horseshoe Falls are the largest and the Bridal Veil Falls the smallest.
The 3 waterfalls combine to produce the highest flow rate of any waterfall on earth.
The largest vertical drop is over 165 feet (50 metres).
The Niagara Falls were created by glacier activity around 10000 years ago.
The Niagara Falls are a source of hydropower, producing large amounts of electricity.
Hydroelectric stations in the area divert less water during the summer when tourist numbers are high, ensuring a spectacular flow of water for visitors.
The Niagara River drains water from Lake Erie into Lake Ontario.
At the current rate of erosion, scientists believe that the Niagara Falls will be gone in around 50000 years, luckily you still have time to see them!
It is illegal (and not very smart) to go over the Niagara Falls.
A number of people have tried it anyway, some survived, some were injured and some were killed.
The first tightrope walker to cross the Niagara Falls did so in 1859.
In 2012 Nik Wallenda became the first person to cross the Niagara Falls by tightrope in 116 years. He did so after receiving permission from both the Canadian and United States governments, although he was required to carry his passport and present it on entry to the Canadian side of the falls.
The Niagara Falls have long been a popular tourist destination, boosted by a number of movies featuring the falls and even a daring performance by famous Illusionist David Copperfield in 1990.
Goat Island sits in the middle of the Niagara Falls, between Horseshoe Falls and Bridal Veil Falls.
A monument dedicated to Serbian-American inventor Nikola Tesla sits on Goat Island.
The Niagara Falls are visited by around 30 million people every year.
The Niagara Falls State Park is the oldest state park in the United States (1885).
George Westinghouse and Nikola Tesla. Seeking to make long distance electric power transmission a reality, they combined their skills, their genius and their belief in a new technology ... alternating current. Together they started a revolution that electrified the world. A Perfect Partnership.
The Niagara Falls is the result of a myriad tons of water, from time immemorial, crashing over the solid limestone cliff, with a force that reduces the limestone to boulders, the boulders to rubble, the rubble to a silt the unabated torrent seizes and carries off down the canyon it has formed and shaped through the eons in this same violent, patient manner.
The Niagara Falls Power Project came as a result of pure technological optimism in 1895 after many attempts and efforts of harnessing the power of the water falls since the first pioneer sawmill had been built there in 1725. But schemes for extracting power had never been adequately conceived.
Five years before start-up of the first large-scale power project at the falls, the method of production and distribution of the power was still undecided. The huge project was to include transmission to Buffalo. Electricity (a novel technology at the time) was only one suggestion. The other methods under consideration were pneumatic, hydraulic, and good old-fashioned mechanical.
While still a student attending school in 1875, at Austrian Polytechnic in Graz, Austria, Nikola Tesla began to think about the possibilities of alternating current.
In 1881 Tesla traveled to Budapest, hoping to work for family friends, Tivadar and Ferenc Puskas. An ambitious promoter, Tivadar had previously convinced Thomas A. Edison to give him the commercial rights to introduce inventions developed by the Wizard of Menlo Park in continental Europe. The Puskas brothers were planning to construct a telephone exchange in Budapest using Edison’s improved telephone design. Unfortunately, they were unable to hire anyone immediately. While waiting, Tesla fell seriously ill. He only recovered with the help of a college friend, Anthony Szigeti, who encouraged the sick man to walk each evening to help regain his strength.
In February 1882, during one of these strolls with Szigeti that Tesla had an epiphany about motors. As they admired the sunset, Tesla suddenly envisioned using a rotating magnetic field in his motor, a fundamental principle in physics and the basis of nearly all devices that use alternating current. Tesla struggled for the next five years to acquire the practical knowledge he needed to realize his motor.
Since his childhood, Tesla himself had dreamed of harnessing the power of the great natural wonder. In his autobiography "My inventions" he told:
"In the schoolroom there were a few mechanical models which interested me and turned my attention to water turbines".
After hearing a description of the great Niagara Falls:
“I pictured in my imagination a big wheel run by the Falls.”
He proclaimed to his uncle that one day "he would go to America and carry out this scheme.”
The working principle of his idea is a magnetic field which rotates in polarity at non-relativistic speeds. This is a key principle to the operation of alternating-current motor. A permanent magnet in such a field will rotate so as to maintain its alignment with the external field. This effect is utilised in alternating current electric motors. Synchronous motors and induction motors use a stator's rotating magnetic fields to turn rotors.
He already though about a multi-phase voltage system while studying in Graz, Austria in 1882. While on assignment to Strasburg, France (Alsace, then a part of Germany) on 1883, Tesla constructs a working brushless polyphase AC induction motor to offer his invention to a German company. It is demonstrated before the former Mayor of the town and to wealthy potential investors. Unfortunately, Tesla is unable to secure financing.
Prodigal Genius - by O' Neill - pp. 56-57:
“The Mayor brought together a number of wealthy Strassburgers. To them the new motor was shown in operation, and the new system and its possibilities described, by both Tesla and the Mayor. The demonstration was a success from the technical viewpoint but otherwise a total loss. Not one member of the group showed the slightest interes.
It was beyond his comprehension that the greatest invention in electrical science, with unlimited commercial possibilities, should be rejected so completely".
After he had helped the Puskas brothers build their telephone exchange in Budapest, Tesla moved with Tivadar to Paris, where they both went to work for the Société Electrique Edison installing incandescent lighting systems.
Nikola worked for about a year for the French branch of the Edison Electric Light Co. At the beginning of 1884, after successfully performed tasks in Strasbourg, he returned to the headquarters of the Edison Continental Company in Paris. Here he improved various electriccomponents used by the Edison Company. During this employment he conceived the idea for the induction motor and other electric equipment that used rotating magnetic fields. But he hoped in vain that the professionals would take interest in his inventions of the rotating magnetic field and asynchronous motor. His remarkable abilities were noticed by Edison's business cohort and close friend Charles Batchelor, the U.S. manager of the French branch of the Edison Company, and he advised him to seek his fortune in the New World. Since he couldn't get anyone in Europe interested in it, Tesla came to the United States to work for Thomas Edison in New York.
In June 1884, Nikola Tesla arrived in the United States. On the way to the boat he actually lost all his possessions (train ticket and personal assets) and he arrived with just 4 cents in his pocket. Anyway the USA was considered the land of the free.
Thanks to the exceptional recommendation by Bachelor and successfully performed test given by Edison (repair of dynamo machines at the Oregon ship) Tesla was employed with Edison Machine Works Company and he became one of the chief engineers and designers. Almost as soon as he arrived at the Goerck Street facility, Mr. Thomas Edison realized the genius of the younger man's work. To this twenty-eight-year old enthusiastic expert Edison gave a very delicate job of redesigning and improvement of dynamo-machines produced in his factories for the ever-increasing market of these devices. Edison also became impressed with him after he successfully performed a number of challenging assignments. The direct current electrification era had begun in the first place with great towns such as New York. But when Tesla asked Edison to let him undertake research on AC, in particular on his concept for an AC motor, Edison rejected the idea. Not only wasn't Edison interested in motors, he refused to have anything to do with the rival current.
Tesla had expected that Edison, being such a great inventor, would perfectly understand and accept the concept of development of alternate currents devices and systems as a more convenient solution for production, transmission, distribution and use of electric energy. So for the time being Tesla threw himself into work on DC. He told Edison he thought he could substantially improve the DC dynamo. Edison told him if he could, it would earn him a $50,000 bonus. This would have enabled Tesla to set up a laboratory of his own where he could have pursued his AC interests. By dint of extremely long hours and diligent effort (his regular hours were from 10:00 am till 5:00 am of the next day), he came up with a set of some 24 designs for new equipment, which would eventually be used to replace Edison's present equipment.
But he never found the promised $50,000 in his pay envelope. When he asked Edison about this matter, Edison told him he had been joking. "You don't understand American humor," he said. In that moment he was deeply disappointed, and for that reason he left Edison's company after less than one year. Tesla only worked there for about six months and he met Edison maybe twice.
Tesla claims, in his autobiographical My Inventions, the following regarding his time at the Machine Works in NY:
For nearly a year my regular hours were from 10.30 A.M. until 5 o'clock the next morning without a day's exception. Edison said to me: "I have had many hard-working assistants but you take the cake." During this period I designed twenty-four different types of standard machines with short cores and of uniform pattern which replaced the old ones. The Manager had promised me fifty thousand dollars on the completion of this task but it turned out to be a practical joke. This gave me a painful shock and I resigned my position.
Tesla assumed that his arc lighting system would be valuable to the Edison organization and that he would handsomely rewarded for his work. However, when that didn’t happen, Tesla quit in disgust and found new backers in Rahway, New Jersey who helped him to patent and build his own arc-lighting system. However, once the Rahway businessmen had a lighting system up and running, they fired Tesla. Destitute, Tesla returned to New York to dig ditches for $2 a day.
Fortunately, Tesla helped dig ditches for the installation of cables connecting the headquarters of the Western Union Telegraph Company with stock and commodity exchanges and he came to the attention of Alfred S. Brown who was supervising the work. Brown took a liking to Tesla and introduced him to Charles Peck, a lawyer who had just made a fortune by forcing Jay Gould to buy his Mutual Union Telegraph Company.
Applies his first patent "Commutator for Dynamo-electric Machines", followed by patents on arc-lamps regulators;
In March 1885 Tesla applied his first patents US334,823 - Commutator for Dynamo Electric Machines - January 26, 1886 (Filed May 18, 1885), US335,786 - Electric Arc Lamp - February 9, 1886 (Filed May 18, 1885) and US335,787 - Electric Arc Lamp - February 9, 1886. These patents were for an improvement in the arc lamp. He used an electromagnet to feed carbons to the arc at a uniform rate to produce a steadier light. Later he applied for patents on arc-lamps regulators and he registered his 'Tesla Arc Light Co' with an aim of implementing his inventions in the field of polyphase alternating currents. Looking for a new high-tech venture, Peck and Brown decided to back Tesla in 1886 and in April 1887, backed by a number of financiers and technicians, Tesla establishes Tesla Electric Company.
In the newly erected laboratory Tesla constructed and demonstrated his first polyphase induction motors and generators. But success was not easily achieved, as his ideas to promote (AC) alternating current was difficult to finance, and by other hand his investors weren't really interested in the development of the AC technology because its future application was still unkown and they were interested just about Tesla's Electric Arc Lamp. His design was a success, but all the money went to the investors. Tesla was soon looking for another opportunity.
Presentation of the Edison Medal to Nikola Tesla: Minutes of the annual meeting of the American Institute of Electrical Engineers, held at the Engineering Societies building - New York City - May 18, 1917:
I realized I would not have produced anything without the scientific training I got, and it is a question whether my surmise as to my possible accomplishment was correct. In Edison's works I passed nearly a year of the most strenuous labor, and then certain capitalists approached me with the project to form my own company. I went into the proposition, and developed the arc light. To show you how prejudiced people were against the alternating-current, as the President has indicated, when I told these friends of mine that I had a great invention relating to alternating-current transmission, they said: —No, we want the arc lamp. We do not care for this alternating-current.— Finally I perfected my lighting system and the city adopted it. Then I succeeded in organizing another company, in April, 1886, and a laboratory was put up, where I rapidly developed these motors, and eventually the Westinghouse people approached us, and an arrangement was made for their introduction. You know what has happened since then. The invention has swept the world.
By 1885 the Italian inventor Galileo Ferraris also builds an induction motor using a two phase configuration like Tesla. However, Ferrari believes incorrectly that such motors can never exceed an efficiency of 50%. Ferraris had concluded in an article (The electrician - December 27, 1895):
"These calculations and experimental results confirm the evident a priori conclusion that an apparatus founded upon this principle cannot be of any commertial importance as a motor"
After some research he lost interest and did not continue with the development of his machines. The famous mathematician and electrical engineer, Charles Proteus Steinmetz came to support the invention of Nikola Tesla. Once noted in his german accent:
"Ferraris built only a little toy, and his magnetic circuits, so far as I know, were completed in air, not in iron, though that hardly makes the difference" (Transactions, A.I.E.E, Vol. VIII, Pg. 591, 1891).
In the case of Ferraris's induction motor, the rotary field was produced by commutating a continuous current and by the other hand the rotary field of Tesla's induction motor was produced by splitting a single-phase alternate current into two phases by proper arrangements of self-induction or condensers (the rotating magnetic field was produced in a dynamo with multiple coils and connected to similar coils in the motor).
The Fig.? shows the first Tesla's induction motor, prior to the year 1884 and altho unique in construction, it developed ¼ horse power at 1800 revolutions per minute and weighed but 20 pounds.
Electro-Motors - The Electrical Review - by Nikola Tesla - April 3rd, 1891:
Fifteen or sixteen years ago, when I was pursuing my course at the college, I was told by an eminent physicist that a motor could not be operated without the use of brushes and commutators, or mechanical means of some kind for commutating the current. It was then I determined to solve the problem.
After years of persistent thought I finally arrived at a solution. I worked out the theory to the last detail, and confirmed all of my theoretical conclusions by experiments. Recognizing the value of the invention, I applied myself to the work of perfecting it, and after long continued labor I produced several types of practical motors.
Now all this I did long before anything whatever transpired in the whole scientific literature — as far as it could be ascertained — which would have even pointed at the possibility of obtaining such a result, but quite contrary at a time when scientific and practical men alike considered this result unattainable. In all civilized countries patents have been obtained almost without a single reference to anything which would have in the least degree rendered questionable the novelty of the invention. The first published essay — an account of some laboratory experiments by Prof.Ferraris — was published in Italy six or seven months after the date of filing of my applications for the foundation patents. The date of filing of my patents is thus the first public record of the invention.
No one can say that I have not been free in acknowledging the merit of Prof.Ferraris, and I hope that my statement of facts will not be misinterpreted. Even if Prof.Ferraris’s essay would have anticipated the date of filing of my application, yet, in the opinion of all fair-minded men, I would have been entitled to the credit of having been the first to produce a practical motor; for Prof. Ferraris himself denies in his essay the value of the invention for the transmission of power, and only points out the possibility of using a properly constructed generator, which is the only way of obtaining the required difference of phase without losses; for even with condensers — by means of which it is possible to obtain a quarter phase — there arc considerable losses, the cost of the condensers not considered.
Thus, in the most essential features of the system—the generators with the two or three circuits of differing phase, the three-wire system, the closed coil armature, the motors with direct current in the field, &c. — I would stand alone, even had Prof, Ferraris’s essay been published many years ago.
US381,968 -Electro Magnetic Motor-May 1, 1888 was filed on October 12, 1887 and on April 22, 1888 Ferraris published a paper in the Royal Academy of Sciences about the AC polyphase motor. Turin, only after reading about Thomson's repulsion motor.
For all these reasons Prof. Ferraris should be denied credit for the invention of the rotating magnetic field machines, not only on legal grounds but on demonstrable grounds as well. Also knowing that by the same rule Marconi was considered the father of radio, after Tesla faulted for not agressively pursuing the commertial development of radio apparatus, even if he demonstrated his wireless experiments in lectures and exibitions many years before than Guglielmo Marconi.
The Edison system used direct current, or DC. Direct current always flows in one direction and is created by DC generators. Edison was a staunch supporter of DC, but it had limitations. The biggest was the fact that DC was difficult to transmit economically over long distances.
Edison knew that alternating current didn't have this limitation, yet he didn't think AC a feasible solution for commercial power systems. Elihu Thomson, one of the principals of Thomson-Houston and a competitor of Edison, believed otherwise. In 1885, Thomson sketched a basic AC system that relied on high-voltage transmission lines to carry power far from where it was generated. Thomson's sketch also indicated the need for a technology to step down the voltage at the point of use.
The DC transmission problem was fundamental. Based on Ohm's Law, efficient and economical transmission requires high voltage (raising the voltage causes increased flow of current, while the resistance remains constant, thus lowering the resistance per unit flow of current). Too high a voltage for practical uses, such as the operation of lights or motors.
With a transformer, alternating current can easily be "stepped up" to high voltages for transmission, or "stepped down" to lower voltages for manufacturing and domestic uses. This cannot be done with direct current.
The Ganz factory in 1884 shipped the world's first five high-efficiency AC transformers. This first unit had been manufactured to the following specifications: 1,400 W, 40 Hz, 120:72 V, 11.6:19.4 A, ratio 1.67:1, one-phase, shell form.
The ZBD patents included two other major interrelated innovations: one concerning the use of parallel connected, instead of series connected, utilization loads, the other concerning the ability to have high turns ratio transformers such that the supply network voltage could be much higher (initially 1,400 to 2,000 V) than the voltage of utilization loads (100 V initially preferred). When employed in parallel connected electric distribution systems, closed-core transformers finally made it technically and economically feasible to provide electric power for lighting in homes, businesses and public spaces.
The other essential milestone was the introduction of 'voltage source, voltage intensive' (VSVI) systems' by the invention of constant voltage generators in 1885. Ottó Bláthy also invented the first AC electricity meter.
The management of Thomson Houston realized that alternating current would be the way of the future and pressed Thomson to provide the technical solutions. He had been working on the problem since 1885 but was blocked by the series connection patented by Gibbs and Gaulard. His efforts were to make self regulating transformers connected in parallel. An AC generator was installed in the Thomson Houston factory in Lynn to provide incandescent lighting and to test the system.
In the Spring of 1885, before opening his electric factory, George Westinghouse purchased the rights in the United States for the use of the Gaulard and Gibbs transformer patents that would "transform" the voltage of alternating current, so that electricity could be carried over long distances at high voltages, then stepped down to the proper voltage for its intended use. Some features of the device he had acquired were impractical, but he hired William Stanley Jr. as chief engineer and other staff for the planned transformer operation and in a few weeks they already worked out a complete new design. He designed and constructed the first commercially-used transformer.
Stanley improved the efficiency and methods of construction by using sheet steel clamped together in a rectangular form. On two sides of the rectangle he wound copper bar induction coils with one coil having five times more turns than the other. The completed transformer had a 500 volt primary and a 100 volt secondary. Stanley was issued US method of construction patent US349,611 A - Induction coil - 21 Sep 1886. It was easy to produce, relatively inexpensive and easy to adjust. It had to be wind to form a core of E-shaped plates in step-up and step-down variations, the central projections of each successive plate being alternately inserted through rewound coils from opposite sides, thus permitting separate winding and consequently the better insulation of the coils.
In a rented plant in Pittsburgh's Garrison Alley the Westinghouse Electric Company was born in 1886. Using the financial success of his air brake operation George Westinghouse and his engineers started the design and building of electrical equipment that used alternating current.
Westinghouse was still flirting with DC power and that infuriated the moody inventor William Stanley Jr. They weren't ready for a divorce so they got a trial separation in December of 1885. Under the new deal Stanley worked out of an office in Massachusetts.
It was first used in Barrington, Massachusetts in March 1886, where he rented a deserted rubber mill for the electrification of the downtown area using an advanced AC power system. he had lit up a small neighborhood with his transformer and an AC generator. The book Networks Of Power by Thomas Parke Hughes described it in detail:
"The length of the transmission circuit from central station laboratory to village center was about 4,000 feet. Connected to it were thirteen stores, two doctors' offices, one barber shop, the telephone exchange, and the post office."
He purchased a 25 horsepower boiler and steam engine to connect the Siemens alternator that Westinghouse imported from England and they located it at the old rubber mill near Cottage Street in Great Barrington, to provide the power for Stanley's pioneering distribution system. This power system was actually placed in operation on March 6, and the following two weeks were utilized for "research and development" before the public demonstration.
In this facility he constructed 26 transformers and used four of these to set up lights in Great Barrington. In the village he lit 13 stores, 2 hotels, 2 doctors' offices, 1 barbershop, and the telephone and post offices. The distance from the generator to the center of town was about 4000 feet. Ten transformers were sent to Pittsburgh to demonstrate a system about two miles long. The success of hydropower plants was evident with additional generating stations built along the Niagara River.
Using this as research materials William Stanley Jr. built his first transformer and it was a lot like the Gaulard and Gibbs's model. For the record, he also had access to the patent papers on the ZBD transformer. Stanley designed and built his own transformers for this installation. He demonstrated their ability to both raise and lower voltage by stepping up the 500-volt output of the Siemens generator to 3000-volts, lighting a string of thirty series-connected 100-volt incandescent lamps, and then stepping the voltage back down to 500-volts.
The spread of Westinghouse and other AC systems triggered a push back in late 1887 by Thomas Edison (a proponent of direct current) who attempted to discredit alternating current as too dangerous in a public campaign called the "War of Currents".
In April 1888 Oliver B. Shallenberger invented an induction meter for measuring alternating current (ampere-hours), a critical element in the Westinghouse AC system.
Early AC systems had a major disadvantage that there was no commercially available AC motor. This shortcoming was solved in fairly short order when the word of the extraordinary Tesla patents reached the academic world, when he was issued his first set of patents for a comprehensive system of AC generators, transformers, synchronous motors and induction motors for the transmission and utilization of two or more phases, what came to be known as the polyphase system. And so it came to pass that the inventor was invited to lecture before the American Institute of Electrical Engineers. George Westinghouse became aware of Tesla in May1, 1888 due to his remarkable speech in Pittsburgh when Tesla introduced his motors and electrical systems in a classic paper, “A New System of Alternate Current Motors and Transformers” which he delivered before the American Institute of Electrical Engineers.
The engineer Elihu Thomson was there and some in the group and he was impressed. The single-circuit induction motor developed by Thomson-Houston still required a commutator, and was still very inefficient. Elihu Thomson rose from his seat and, after praising Tesla's: "new and admirable little motor" he declared that he had for some time been working along similar lines toward the same goal:
"The trials which I have made have been by the use of a single alternating circuit, not a double alternating circuit".
When Tesla's agents offered the patents to Thomson-Houston, he dissmissed them as not worth the cost of securing them. He may actually believed this or he may has seen them as a threat to his own system. On the other hand, acquiring the patents would imply the contract with Tesla in his company, but Thomson didn't like other inventors mucking around his domain. Anyway, Thomson followed Edison's lead in rejecting the doorway to the future proferred by Tesla.
Westinghouse promptly dispatched Guido Pantaleoni to Italy to buy the Ferraris's patents, paying the munificient sum of 5000 lire - $1000 for such right. Just as he had done a year earlier in securing patent control over AC transformers. However, closer inspection of Tesla's patents convinced the American entrepreneur that the Italian patents would be of little use. Shallenberger expressed his concern to Westinghouse that the Tesla patents might prevent the company from succesfully development an AC motor. In response Westinghouse dispatched Henry. M Byllesby, vice president of Westinhouse Electric and Thomas B. Kerr, general counsel, to New York in late May 1888 after one week of Tesla's lecture and he did not commit the same mistake as Thomson or Edison. In fact Tesla's progress on the motor was ahead of Oliver Shallenberger's 3 phase electric motor. Two months later, George Westinghouse acquired the patent rights and Tesla’s services and he also introduces the induction ampere-hour meter for alternating current developed by Oliver B. Shallenberger.
Tesla conceived that by providing the armature of his generator and the field of his motor with two more sets of coils, connected so as to form distinct circuits, he would be able to produce a progressive shifting of the magnetic poles of the motor field, and thus drag around an armature capable of magnetic induction and placed within the sphere of influence of his rotating field. This method of operation will be clearly understood from the diagrammatic sketch A (Fig. 6) and the illustration (Fig. 7) showing a diagram of the connections of the motor and generator circuits. Considering the latter first, M is the motor and G the generator. The armature A of the generator is wound with two sets of coils, B and B', brought out through the shaft and connected with the contact rings b b and b' b'.
The field magnet of the motor consists of the iron ring R, also wound with two sets of coils, C C and C' C', the diametrically opposite coils being connected together in series. The generator coils B and the motor coils C' C' it will be seen are included in one circuit L, and the remaining generator coils B' and the motor coils C C in another circuit L'. The armature of the motor consists simply of a disk of iron cut away at the sides, which becomes a magnet by induction when the motor field is energized. Turning to Fig. 6, B and B' represent the coils of the generator armature and C and C' those of the motor field as in Fig. 7. When the generator coils are in the position shown in the first diagram the coil B is generating no current and B' is generating its maximum amount. The coils C of the motor field, which are included in the circuit of B', are therefore traversed by their greatest current and produce magnetic poles in the iron ring R at N and S. As the generator armature revolves, B is brought to a position in which it is generating current, and when this movement amounts to one eighth of a revolution the circle will be in the position shown in the second diagram of the figure. Each of the pair of coils C and C' will now tend to set up poles in the ring R of the motor ninety degrees from each other, and as their action is equal and opposite, the position of the poles will be determined by the resultant of the magnetic forces acting on the ring, and the poles will therefore be shifted around the ring an eighth of a revolution. They will be shifted another eighth when the generator armature reaches the position shown in the last diagram, and will be successively displaced around the ring R as this armature revolves until a complete revolution has been made, when the parts are in their original position and ready to repeat the same cycle of operations.
The principle of the rotation of the magnetic poles had been applied by Mr. Tesla to a great variety of constructions. He had designed machines in which the field magnetism remains fixed and that of the armature is shifted, and others again in which there is a progressive shifting of the magnetic poles of both the field and armature in opposite directions. He had also found that the motor armature may consist of sets of closed coils, currents being developed in them by induction, and by making the induced portion of the generator stationary and the field revolving he has been able to produce apparatus free from all movable electrical contacts. In operating motors of this character Mr. Tesla usually employed a generator with multiple armature circuits as described above; but in the course of his experiments he discovered that the ordinary continuous or direct current machine could by slight alterations be made to furnish an alternating multiphase current as well as and in addition to the direct current. To accomplish this he found it was only necessary to add to the machine a pair of collector rings for each circuit of the multiphase current, and connect them with the proper armature coils. If, for instance, he desired to produce a two-phase current requiring two circuits from his generator to his motor, one circuit would include a set of coils in the armature of the generator that were passing through the position in which the maximum current was being produced, and the other a set of coils in which at the same time the minimum current was being generated. The phases of the current would then follow each other in the same order as in the previous machines with distinct circuits on the armature. With this form of machine a multiple- phase alternating current, it will be seen, can be taken off from the collector rings, while a direct current can be taken from the commutator, and a part or the whole of this direct current be sent through the field coils to energize them and then put to any use for which such currents are suitable.
One day Westinhouse visited Tesla’s laboratory and was amazed at what he saw. Tesla had constructed a model polyphase system consisting of an alternating current dynamo, step-up and step-down transformers and A.C. motor at the other end. The perfect partnership between Tesla and Westinghouse for the nationwide use of electricity in America had begun.
Nikola Tesla on his work with alternating currents and Their Application to Wireless Telegraphy, Telephony and Transmission of Power: An Extended Interview- Leland I. Anderson, Editor:
In order to increase the number of breaks, I employed currents of different phase. I had in my laboratory, permanently, a two-phase dynamo and could get phases between; that is, from two phases, 90 apart, I could obtain four phases, 45 apart. Here is an arrangement shown as I had it, working with three phases (60 apart, and could obtain six phases, 30 apart), and later on I had one with four phases (45 apart, and could obtain eight phases 22 1/2 apart). You see, as I multiplied the number of the phases, I increased the number of the fundamental discharges.
This I employed already in the 35 South Fifth Avenue laboratory, because I remember that I gave entertainments to several scientific societies and it was then present there. I know on one occasion there was the Society of Architects, and another, the Electrotherapeutic Society, and then I had distinguished men like Mark Twain and Joseph Jefferson -- I gave them a demonstration which was published in Martin's article in the Century Magazine of April 1895, and I know that on these occasions I used a two-phase arrangement. Later on I made it four phase. That apparatus existed, therefore, prior to the destruction of my laboratory in 1895.
He never developed his inventions with any comertial intention, and he allways had the confidence that the necessary fundings would materialize somehow by its own importance. In the case of the Alternating Current, the opportunity came in late 1893 from the important inventor and buisness man from Pittsburgh, George Westinghouse, who made his fortune by manufacturing his invention of air brakes for the burgeoning railroad industry. Westinghouse was awarded the contract to create the powerhouse and Tesla told to the industrialist about his idea for the polyphase system, which would allow alternating current (AC) electricity to be transmitted over large distances.
Westinhouse was very interested in the concept developed by Tesla but the exact terms and conditions of the agreement does not appear in the historical records. Many sources suggested that Tesla received $ 1 million for his more than 40 patents but the most credible record is probablly that he was paid $60,000 with 90% being in Westinghouse stock and a royalty of $2.50 per installed kW.
When Byllesby and Kerr expressed an interest in buying the patents for Westinghouse, Peck informed them that a San Francisco capitalist had offered 2000.000 $ plus a royality of $2.50 per horsepower for each motor installed.
"The terms, of course, are monstruous" Byllesby told Westinhouse "I told them that there was no possibility of our considering the matter seriously". "In order to avoid giving the impression that the matter was one which excited my curiosity I made my visit short".
Westinghouse once commented:
"The price seems rather high, but if it is the only method for operating a motor by the alternating current, and if it is applicable to street car work, we can unquestionably easily get from the users of the apparatus whatever taxes put upon it by the inventors"
In addition, he hires Tesla as a consultant for his company for one year and he moved to Pittsburgh in July 1888 in order to put his AC motor designs into production. While in Pittsburgh, Tesla left Szigeti in New Yorkwhere he continued to work on several motor patents that Tesla had not assigned to Westinghouse.
During his time in Pittsburgh, Tesla worked closely with Shallenbergerand some other important engineers and inventors and he developed a great admiration for George Westinghouse.
Tesla initially worked on improving two polyphase motors that he brought from New York, anticipating that Westinghouse would develop a whole new polyphase system, using four wires to connect the generators and motors. Since his motors worked best on low frequencies, Tesla set up his motors to run on 50 cycles and he experimented with new transformer designs. The Westinghouse designs were using 133 cycles so that consumers wouldn't complain about their incandescent lamps flickering. Tesla finally agreed to work a split-phase version that could be put into production. He and the other Westinghouse engineers adapted the motor by increasing the amount of coper-wire in the rotor and replacing the wrought-iron cores of the rotor and stator with soft Bessemer steel. The change to steel cores alone doubled the work of a typical motor could preform and the Westinghouse company treated this discovery as a secret it jealously guarded for years. Tesla also worked with the chief Westinghouse designer Albert Schmid, to develop a standard frame for the stator that could be easily cast and machined. While working on these changes, Tesla prepared the patents for Westinghouse and in 1889 he filed fifteeh patents. In terms of patents this was the most productive year in his career *.
Tesla usually didn't put his ideas in writing or sketches and the engineers in Pittsburgh had to improve original patents as they were under the gun to get projects completed. The main problem that plagued the Tesla design was starting the motor under load in small stations. A few years later (in 1893) Charles Proteus Steinmetz working as independent contractor was involved in fixing some thermal/electrical issue. Advancing studies begun by Nikola Tesla (See the Tesla patent US417,794 - Armature for Electric Machines - A. Schmid & N. Tesla - December Dec 24, 1889 ), Steinmetz's research on hysteresis (a magnetic phenomenon that caused power loss in motors) was applied to the design of AC circuits, and resulted in precise calculations of magnetic resistance which revolutionized AC circuit theory and analysis.
In 1889 the Westinghouse Electric Company renames itself as the Westinghouse Electric & Manufacturing Company. By the same year the Niagara Falls company made financing arrangements with a banking group that comprised J.P. Morgan, Brown Brothers, Windslow and Lanier & Co. Before Windslow, Lanier agreed to participate, it had send a partner, Edward Dean Adams to investigate. Niagara Falls Power Company, a descendant of Schoellkopf's firm, formed the Cataract Company headed by Edward Dean Adams, with the intent of expanding Niagara Falls power capacity.
Tesla left the Westinghouse plant in the fall of 1889, and he had immediately turned to the next phase of his development of the alternating-current field: a new system of distributing energy by means of high-frequency alternating currents which would be a far more magnificent discovery than his polyphase system. Within the next two years he had explored the principles by which energy could be distributed broadcast without the use of wires, and these he had demonstrated with powerful coils in his laboratory. The distribution of intelligence, later called 'wireless', was but a single phase of his world-wide system.
On 1890 Adams became the president of the cataract construction and he soon left for Europe (supposedly not to find financing but to obtain technological information). He called Rothschild in London to explain the plans for the utilization of Niagara falls and the british banker reccomended engineers and then as Adams recalled, the banker asked:
"I suppose you are not ready with your financial plans?"
"yes" replayed the president Adams - "they had been adopted to a preliminary extent... All previous efforts to utilize Niagara power in a important way have been failures, but we believe that science has so advanced that, with its skillfull use, it soon may be possible to harness Niagara upon comertial basis".
Adams told to Rothschild:
"we have not come for money, but for advice. We wish to begin by investing in the counsel of your scientists and engineers"
Lord Rothschild found this request from an American rare, and according to Adams made an initial suscription of £5.000 as a result of the interview, but in fact nothing was rare and the president was just opening the way for foregin capital.
A flood destroyed the Willamette Falls DC power station. This unfortunate event paved the way for the first long distance transmission of AC electricity in the world when Willamette Falls Electric company installed experimental AC generators from Westinghouse in 1890. That same year, the Niagara Falls Power Company (NFPC) and its subsidiary Cataract Company formed the International Niagara Commission composed of experts, to analyze proposals to harness Niagara Falls to generate electricity. The commission was led by Sir William Thomson (later Lord Kelvin) and included Eleuthère Mascart from France, William Unwin from England, Coleman Sellers from the US, and Théodore Turrettini from Switzerland. It was backed by entrepreneurs such as J. P. Morgan, Lord Rothschild, and John Jacob Astor IV. Among 19 proposals, they even briefly considered compressed air as a power transmission medium, but preferred electricity. Anyway they could not decide which method would be best overall.
In 1890 George Westinghouse recommended that the best way to transport Niagara Falls power to Buffalo would be by compressed air (compressed-air or water mains or steel cables on posts and pulleys the 22-mile distance from Niagara Falls to Buffalo). Westinghouse was likely to know. As the inventor of the air brake, he was the acknowledged expert on pneumatic systems. And of late he had turned his attention to electricity. In 1886 he had organized the Westinghouse Electric Company. By 1890, the company was operating 300 central generating stations.
When Nikola Tesla invented the three-phase system of alternating current power transmission, distant transfer of electricity became possible, as Westinghouse and Tesla had built the AC-power Ames Hydroelectric Generating Plant in Telluride in 1890 and proved it effective transmitting electricity to 2.6 miles (4.2 km) by using a motor-driven stamp mill at the Gold King Mine. It began operation in 1891.
Edison's DC distribution system consisted of generating plants feeding heavy distribution conductors, to customer loads primarily lighting and motors. The system operated at the same voltage level throughout; for example, 100 volt lamps at the customer's location would be connected to a generator supplying 110 volts, the margin allowed for some voltage drop in the wires between the generator and load. The voltage level was chosen for convenience in lamp manufacture; high-resistance carbon filament lamps could be constructed to withstand 100 volts, and to provide lighting performance economically competitive with gas lighting. At the time it was felt that 100 volts was not likely to present a severe hazard of fatal electric shock.
To save on the cost of copper conductors, a three-wire distribution system was used. The three wires were at +110 volts, 0 volts and −110 volts relative potential. 100-volt lamps could be operated between either the +110 or −110 volt legs of the system and the 0-volt "neutral" conductor, which carried only the unbalanced current between the + and − sources. The resulting three-wire system used less copper wire for a given quantity of electric power transmitted, while still maintaining (relatively) low voltages. Even with this innovation, the voltage drop due to the resistance of the system conductors was so high that generating plants had to be located within a mile (1–2 km) or so of the load. Higher voltages could not so easily be used with the DC system because there was no efficient low-cost technology that would allow reduction of a high transmission voltage to a low utilization voltage.
Unable to challenge AC electricity on technical merits, Edison turned to using scare tactics instead and carried out a campaign to discourage the use of alternating current, including spreading disinformation on fatal AC accidents, publicly killing animals, and lobbying against the use of AC in state legislatures. "Just as certain as death (AC power) will kill a customer within six months," he declared. Leaflets about the dangers of AC current were printed and distributed. Lobbying efforts were made in New York State to limit legal levels of electricity to 800 volts, making AC distribution impractical "as a matter of public safety". Perhaps most horrifying, though, were Edison's weekend demonstrations of the dangers of Tesla's work. Taking one of the frightened pets stolen from the streets of West Orange, Edison would place it on a sheet of metal, bring forth two wires attached to an AC generator, and announce to spectators:
"Ladies and gentlemen, I shall now demonstrate the effects of AC current on this dog."
Edison directed his technicians, primarily Arthur Kennelly and Harold P. Brown, to preside over several AC-driven killings of animals, primarily stray cats and dogs but also unwanted cattle and horses. Acting on these directives, they were to demonstrate to the press that alternating current was more dangerous than Edison's system of direct current. He also tried to popularize the term for being electrocuted as being "Westinghoused". Years after DC had lost the "war of the currents," in 1903, his film crew made a movie of the electrocution with high voltage AC, supervised by Edison employees, of Topsy, a Coney Island circus elephant which had recently killed three men.
The Edison's intention to disparage the system of alternating current led to the invention of the electric chair. Harold P. Brown, who was being secretly paid by Edison, built the first electric chair for the state of New York to promote the idea that alternating current was deadlier than DC.
When the chair was first used, on August 6, 1890, the technicians on hand misjudged the voltage needed to kill the condemned prisoner, William Kemmler. The first jolt of electricity was not enough to kill Kemmler, and only left him badly injured. The procedure had to be repeated and a reporter on hand described it as "an awful spectacle, far worse than hanging." George Westinghouse commented:
"They would have done better using an axe."
Mikhail Dolivo-Dobrowolsky (Russian, naturalized Swiss), chief electrician at the AEG in Berlin used the basic ideas of Tesla and constructed the first three-phase cage induction motor. In the beginning of 1889, his first motor is running properly. His system was displayed for first time in Europe at the International Electro-Technical Exhibition of 1891, where Dolivo-Dobrovolsky used this system to transmit electric power at the distance of 176 km with 75% efficiency.
Mr. Hering wrote in the article Mr. Tesla And The Drehstrom System - Electrical World - February 6, 1892:
"Dobrowolsky, though he may have been an independent inventor, admits Tesla's work is prior to his invention. The modesty of both of these gentlemen would, I feel sure, lead to a clear understanding. Regarding the subject of priority it may be of interest here to say that in a conversation with Prof. Ferraris last summer that gentleman told me with very becoming modesty that, although he had experimented with the rotary field several years before Tesla's work was published he did not think it was possible that Tesla could have known of his work and he therefore believed Tesla invented it entirely independently. He also stated that Tesla developed it much further than he (Ferraris) did".
By that time the key to electrical power distribution, was a power transformer developed by Lucien Gaulard and John Dixon Gibbs which was demonstrated in London in 1881, and attracted the interest of Westinghouse. The Gaulard-Gibbs design was one of the first that could handle large amounts of power and was easily manufactured.
William Stanley Jr. was an electrician who worked with tele keys and fire alarms of an early manufacturer which was investigating the AC current and in 1884 went to work in Pittsburgh with Westinghouse to solve some problems in AC distribution. He lost a great deal of time trying to convert DC to AC power for experiments because he had no alternator to work with (like Ferraris's experiments).
In 1885, Westinghouse imported a number of Gaulard-Gibbs transformers and a Siemens primitive AC generator from England to develop some experiments at his home in Pittsburgh. With this material Westinghouse instructed Stanley and his assistants, Albert Schmid and Oliver B. Shallenberger, to investigate on the Gaulard and Gibbs system to determine the commercial value and to begin experimenting with AC networks. Albert Schmid was a Swiss mechanical and electrical engineer who had worked on some of the earliest dynamos and arc lamp systems in Europe and Oliver B. Shallenberger was another engineer and inventor who also worked for Westinhouse since 1884.
In the autumn of 1884, Károly Zipernowsky, Ottó Bláthy and Miksa Déri (ZBD), three engineers associated with the Ganz factory, had determined that open-core devices were impracticable, as they were incapable of reliably regulating voltage. In their joint 1885 patent applications for novel transformers (later called ZBD transformers), they described two designs with closed magnetic circuits where copper windings were either wound around iron wire ring core or surrounded by iron wire core. In both designs, the magnetic flux linking the primary and secondary windings traveled almost entirely within the confines of the iron core, with no intentional path through air (see Toroidal cores below). The new transformers were 3.4 times more efficient than the open-core bipolar devices of Gaulard and Gibbs.