Michael Faraday was one of the greatest scientists of the 19th century. His early life closely paralleled that of Benjamin Franklin. Both were part of a large family; both were apprenticed in the printing trade; both read voraciously and became self-educated; and both loved science.
Faraday was born in "Newington, Surrey, England, on September 22, 1791". His father, a blacksmith, could not afford a formal education for Michael, and so the boy received just the bare essentials and was apprenticed to a bookbinder.In some ways this apprenticeship was a stroke of good fortune for Michael because it gave him the opportunity to read all that he desired. He studied thearticles about electricity in the Encyclopaedia Britannica,read a chemistry textbook, and was very interested in magnetism. In 1812 Faraday obtained tickets to attend the lectures of Humphry Davy at the Royal Institution.Faraday took 386 pages of notes and had them bound in leather and sent to SirJoseph Banks (1743-1820), who was president of the Royal Society of London,with the hope of making a favorable impression. Unfortunately, Banks never responded. No matter--Faraday then sent a copy directly to Davy along with a job application to be Davy's assistant. Davy was very impressed, but he alreadyhad an assistant. However, shortly thereafter, Davy fired his assistant forbrawling, contacted Faraday, and offered him the job of "washing bottles." This was not exactly what Faraday had in mind, but it was a step in the right direction and he accepted.
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| Michael Faraday |
In 1813 Davy resigned his post at the Royal Institution, married a wealthy widow, and began an extended trip through Europe. The trip afforded Faraday theopportunity to meet such famous men as Italian physicist Alessandro Volta and French chemist Louis-Nicolas Vauquelin (1763-1829). In 1820, Danish physicist Hans Christian Oersted (1777-1851) had discovered that an electric currentproduced a magnetic field. This had set off a flurry of investigation by other scientists, among them Faraday, who was now back in England. Within a yearof Oersted's discovery, Faraday had built a device which essentially consisted of a hinged wire, a magnet and a chemical battery. When the current was turned on, a magnetic field was set up in the wire, and it began to spin aroundthe magnet. Faraday had just invented the electric motor.
Faraday's motor was certainly an interesting device, but it was treated as atoy. But Faraday had a greater goal in sight. Oersted had converted electriccurrent into a magnetic force; Faraday intended to reverse the process and create electricity from magnetism. Taking an iron ring, Faraday wrapped half ofit with a coil of wire that was attached to a battery and switch. André Marie Ampère (1775-1836) had shown that electricity would set up amagnetic field in the coil. The other half of the ring was wrapped with a wire that led to a galvanometer. In theory, the first coil would set up a magnetic field that the second coil would intercept and convert back to electric current which the galvanometer would register. Faraday threw the switch and received instant gratification: the experiment worked, a device that became known as the transformer. However, the result was not exactly what he expected. Instead of registering a continuous current, the galvanometer moved only whenthe circuit was opened or closed. Ampère had observed the same effecta decade earlier but ignored it because it did not fit his theories. Decidingto make the theory fit the observation, instead of the other way around, Faraday concluded that when the current was turned on or off, it caused magnetic"lines of force" from the first coil to expand or contract across the secondcoil, inducing a momentary flow of current in the second coil. In this way Faraday discovered the principle of electrical induction.
Meanwhile, in the United States, physicist Joseph Henry had independently made the same discovery. Faraday's affiliation with Davy had been suffering because Davy was extremely jealous of his former assistant, who was now eclipsinghim. The situation escalated following Faraday's invention of the transformer; Davy claimed the idea for the experiment had been his. When Faraday was nominated to become a member of the Royal Society in 1824, Davy cast the only negative vote.
Having shown that magnetism could produce electricity, Faraday's next goal was to produce a continuous current instead of just a momentary spurt. This time he decided to reverse an experiment made by Dominique Arago (1786-1853). In 1824 Arago had discovered that a rotating copper disk deflected a magnetic needle. This, explained Faraday, was an example of magnetic induction. Faradayplanned to use a magnetic field to set up an electric current. In 1831 Faraday took a copper disk and spun it between the poles of a permanent magnet. This set up an electric current in the disk which could be passed through a wire and put to work. So long as the wheel spun, current was produced. This simple experiment produced the greatest electrical invention in history: the electric generator. It took five decades and other inventions to make generatorspractical, but Faraday had pointed the way.
Faraday is especially remembered for his use of intuition in his scientific discoveries, making minimal use of mathematics. Unfortunately, he suffered a mental breakdown in 1839 from which he never fully recovered, and he was forced to leave the laboratory work to others. In addition to his inventions, he had compiled a number of notable discoveries: "magnetic lines of force," the compound benzene, how to liquify various gasses, and the laws of electrolysis.He also developed the concept of a "field"--a force, like magnetism or electric fields or gravity, that extends throughout space and is produced by magnets or electric charge or, in the case of gravity, mass. James Clerk Maxwell later developed his famous equations describing electromagnetism using this concept, acknowledging his debt to Faraday.
On August 25, 1867, Faraday died at Hampton Court, Middlesex, England. His accomplishments were all the more remarkable considering he had had no formal training in science or mathematics, yet was able to establish the fundamentalnature of electricity and magnetism.
