Saturday, March 14, 2020
Early Inventors and Innovators of Electricity
Early Inventors and Innovators of Electricity The history of electricity begins with William Gilbert, a physician who served Queen Elizabeth the first of England. Before William Gilbert, all that was known about electricity and magnetism was that the lodestone possessed magnetic properties and that rubbing amber and jet would attract bits of stuff to start sticking. In 1600, William Gilbert published his treatise De magnete, Magneticisique Corporibus (On the Magnet). Printed in scholarly Latin, the book explained years of Gilberts research and experiments on electricity and magnetism. Gilbert raised the interest in the new science greatly. It was Gilbert who coined the expression electrica in his famous book. Early Inventors Inspired and educated by William Gilbert, several Europeans inventors, including Otto von Guericke of Germany, Charles Francois Du Fay of France, and Stephen Gray of England expanded the knowledge. Otto von Guericke was the first to prove that a vacuum could exist. Creating a vacuum was essential for all kinds of further research into electronics. In 1660, von Guericke invented the machine that produced static electricity; this was the first electric generator. In 1729, Stephen Gray discovered the principle of the conduction of electricity. In 1733, Charles Francois du Fay discovered that electricity comes in two forms which he called resinous (-) and vitreous (), now called negative and positive. The Leyden Jar The Leyden jar was the original capacitor, a device that stores and releases an electrical charge. (At that time electricity was considered the mysterious fluid or force.) The Leyden jar was invented in Holland in 1745 and in Germany almost simultaneously. Both Dutch physicist Pieter van Musschenbroek and German clergyman and scientist, Ewald Christian Von Kleist invented a Leyden jar. When Von Kleist first touched his Leyden jar he received a powerful shock that knocked him to the floor. The Leyden jar was named after Musschenbroeks hometown and university Leyden, by Abbe Nolett, a French scientist, who first coined the term Leyden jar. The jar was once called the Kleistian jar after Von Kleist, but this name did not stick. History of Electricity - Ben Franklin Ben Franklins important discovery was that electricity and lightning were one and the same. Ben Franklins lightning rod was the first practical application of electricity. History of Electricity - Henry Cavendish and Luigi Galvani Henry Cavendish of England, Coulomb of France, and Luigi Galvani of Italy made scientific contributions towards finding practical uses for electricity. In 1747, Henry Cavendish started measuring the conductivity (the ability to carry an electrical current) of different materials and published his results. In 1786, Italian physician Luigi Galvani demonstrated what we now understand to be the electrical basis of nerve impulses. Galvani made frog muscles twitch by jolting them with a spark from an electrostatic machine. Following the work of Cavendish and Galvani came a group of important scientists and inventors, including Alessandro Volta of Italy, Hans Oersted of Denmark, Andre Ampere of France, Georg Ohm of Germany, Michael Faraday of England, and Joseph Henry of America. Work With Magnets Joseph Henry was a researcher in the field of electricity whose work inspired many inventors. Joseph Henrys first discovery was that the power of a magnet could be immensely strengthened by winding it with insulated wire. He was the first person to make a magnet that could lift 3,500 pounds of weight. Joseph Henry showed the difference between quantity magnets composed of short lengths of wire connected in parallel and excited by a few large cells, and intensity magnets wound with a single long wire and excited by a battery composed of cells in series. This was an original discovery, greatly increasing both the immediate usefulness of the magnet and its possibilities for future experiments. Michael Faraday,à William Sturgeon, and other inventors were quick to recognize the value of Joseph Henrys discoveries. Sturgeon magnanimously said, Professor Joseph Henry has been enabled to produce a magnetic force which totally eclipses every other in the whole annals ofà magnetism, andà no parallel is to be found since the miraculous suspension of the celebrated Oriental impostor in his iron coffin. Joseph Henry also discovered the phenomena ofà self-inductionà and mutual induction. In his experiment, a current sent through a wire in the second story of the building induced currents through a similar wire in the cellar two floors below. Telegraph A telegraph was an early invention that communicated messages at a distance over a wire using electricity that was later replaced by the telephone. The word telegraphy comes from the Greek wordsà teleà which means far away andà graphoà which means write. The first attempts to send signals by electricity (telegraph) had been made many times beforeà Joseph Henryà became interested in the problem.à William Sturgeonsà invention of the electromagnet encouraged researchers in England to experiment with the electromagnet. The experiments failed and only produced a currentà that weakened after a few hundred feet. The Basis for the Electric Telegraph However, Joseph Henry strung a mile of fine wire, placed an intensityà batteryà at one end, and made the armature strike a bell at the other. Joseph Henry discovered the essential mechanics behind the electric telegraph. This discovery was made in 1831, a full year beforeà Samuel Morseà invented the telegraph. There is no controversy as to who invented the first telegraph machine. That was Samuel Morses achievement, but the discovery which motivated and allowed Morse to invent the telegraph was Joseph Henrys achievement. In Joseph Henrys own words: This was the first discovery of the fact that a galvanic current could be transmitted to a great distance with so little a diminution of force as to produce mechanical effects, and of the means by which the transmission could be accomplished. I saw that the electric telegraph was now practicable. I had not in mind any particular form of telegraph, but referred only to the general fact that it was now demonstrated that a galvanic current could be transmitted to great distances, with sufficient power to produce mechanical effects adequate to the desired object. Magnetic Engine Joseph Henry next turned to designing a magnetic engine and succeeded in making a reciprocating bar motor, on which he installed the first automatic pole changer, or commutator, ever used with an electric battery. He did not succeed in producing direct rotary motion. His bar oscillated like the walking beam of a steamboat. Electric Cars Thomas Davenport, a blacksmith from Brandon, Vermont, built anà electric carà in 1835, which was road worthy. Twelve years later Moses Farmer exhibited an electric-driven locomotive. In 1851, Charles Grafton Page drove an electric car on the tracks of the Baltimore and Ohio Railroad, from Washington to Bladensburg, at the rate of nineteen miles an hour. However, the cost of batteries was too great and the use of the electric motor in transportation not yet practical. Electric Generators The principle behind the dynamo or electric generator was discovered byà Michael Faradayà andà Joseph Henryà but the process of its development into a practical power generator consumed many years. Without a dynamo for the generation of power, the development of the electric motor was at a standstill, and electricity could not be widely used for transportation, manufacturing, or lighting like it is used for today. Street Lightsà The arc light as a practical illuminating device was invented in 1878 by Charles Brush, an Ohio engineer and graduate of the University of Michigan. Others had attacked the problem of electric lighting, but a lack of suitable carbons stood in the way of their success. Charles Brush made several lamps light in series from one dynamo. The first Brush lights were used for street illumination in Cleveland, Ohio. Other inventors improved the arc light, but there were drawbacks. For outdoor lighting and for large halls arc lights worked well, but arc lights could not be used in small rooms. Besides, they were in series, that is, the current passed through every lamp in turn, and an accident to one threw the whole series out of action. The whole problem of indoor lighting was to be solved by one of Americas most famous inventors. Thomas Edison and Telegraphy Edison arrived in Boston in 1868, practically penniless, and applied for a position as night operator. The manager asked me when I was ready to go to work. Now, I replied. In Boston he found men who knew something of electricity, and, as he worked at night and cut short his sleeping hours, he found time for study. He bought and studied Faradays works. Presently came the first of his multitudinous inventions, an automatic vote recorder, for which he received a patent in 1868. This necessitated a trip to Washington, which he made on borrowed money, but he was unable to arouse any interest in the device. After the vote recorder, he says, I invented aà stock ticker, and started a ticker service in Boston; had 30 or 40 subscribers and operated from a room over the Gold Exchange. This machine Edison attempted to sell in New York, but he returned to Boston without having succeeded. He then invented a duplex telegraph by which two messages might be sent simultaneously, but at aà test, th e machine failed because of the stupidity of the assistant. Penniless and in debt, Thomas Edison arrived again in New York in 1869. But now fortune favored him. The Gold Indicator Company was a concern furnishing to its subscribers by telegraph the Stock Exchange prices of gold. The companys instrument was out of order. By a luckyà chance, Edison was on the spot to repair it, which he did successfully, and this led to his appointment as superintendent at a salary of three hundred dollars a month. When a change in the ownership of the company threw him out of the position he formed, withà Franklin L. Pope, the partnership of Pope, Edison, and Company, the first firm of electrical engineers in the United States. Improved Stock Ticker, Lamps, and Dynamos Not long afterward Thomas Edison released the invention which started him on the road to success. This was the improved stock ticker, and the Gold and Stock Telegraph Company paid him 40,000 dollars for it, more money than he had expected. I had made up my mind, Edison wrote, that, taking into consideration the time and killing pace I was working at, I should be entitled to $5000, but could get along with $3000. The money was paid by check and Thomas Edison had never received a check before, he had to be told how to cash it. Work Done in the Newark Shop Thomas Edison immediately set up a shop in Newark. He improved the system of automatic telegraphy (telegraph machine) that was in use at that time and introduced it into England. He experimented with submarine cables and worked out a system of quadruplex telegraphy by which one wire was made to do the work of four. These two inventions were bought byà Jay Gould, owner of the Atlantic and Pacific Telegraph Company. Gould paid 30,000à dollarsà for the quadruplex system but refused to pay for the automatic telegraph. Gould had bought the Western Union, his only competition. He then, wrote Edison, repudiated his contract with the automatic telegraph people and they never received a cent for their wires or patents, and I lost three years of very hard labor. But I never had any grudge against him because he was so able in his line, and as long as my part was successful the money with me was a secondary consideration. When Gould got the Western Union I knew no further progress in telegraphy was possible, and I went into other lines. Work for the Western Union In fact, however, lack of money forced Edison to resume his work for the Western Union Telegraph Company. He invented a carbon transmitter and sold it to the Western Union for 100,000 dollars, paid in seventeen annual installments of 6,000 dollars. He made a similar agreement for the same sum for the patent of the electro-motograph. He did not realize that these installments payments were not good business sense. These agreements are typicalà of Edisons early yearsà as an inventor. He worked only upon inventions he could sell and sold them to get the money to meet the payrolls of his different shops. Later the inventor hired keen businessmen toà negotiateà deals. Electric Lamps Thomas Edison set up laboratories and factories atà Menlo Park, New Jersey, in 1876, and it was there that he invented theà phonograph, patented in 1878. It was in Menlo Park that he began a series of experiments which produced hisà incandescent lamp. Thomas Edison was dedicated to producing anà electric lamp for indoor use. His first research was for a durable filament which would burn in a vacuum. A series of experiments with a platinum wire and various refractory metals had unsatisfactory results. Many other substances were tried, even human hair. Edison concluded that carbon of some sort was the solution rather than a metal. Joseph Swan, an Englishman actually came to the same conclusion first. In October 1879, after fourteen months of hard work and the expenditure of forty thousand dollars, a carbonized cotton thread sealed in one of Edisons globes was tested and lasted forty hours. If it will burn forty hours now, said Edison, I know I can make it burn a hundred. And so he did. A better filament was needed. Edison found it in carbonized strips of bamboo. Edison Dynamo Edison developed his own type ofà dynamo, the largest ever made up to that time. Along with the Edison incandescent lamps, it was one of the wonders of the Paris Electrical Exposition of 1881. Installation in Europe and America of plants for electrical service soon followed. Edisons first great central station, supplying power for three thousand lamps, was erected at Holborn Viaduct, London, in 1882, and in September of that year the Pearl Street Station in New York City, the first central station in America, was put into operation.
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