Henry Joseph

Amazing coincidences happen in life. Youthful years of Joseph Henry and his first infatuation scientific literature closely resemble the early years of his distinguished contemporary, Michael Faraday: without knowing anything about each other, . Being self-taught, . living on different continents, . they almost simultaneously discovered the phenomenon of electromagnetic induction, . that was the beginning of modern electrical engineering and telecommunications.,

. Henry, . as Faraday, . Born into a poor family of a modest U.S. carrier (17 December 1797) He was a child was sent to her grandmother's farm, . where he attended rural school and also worked part time in life as a messenger from a local dealer,
. One thirteen-year boy in pursuit of the runaway rabbit got through a tunnel under the village church in the upper enclosed space, the library caught up with many exciting books. He had only learned to read books and literally fascinated him, he began reading them one after the other (remember, like Faraday, a boy working in the bookbinding studio, suddenly came across a huge volume "Encyclopaedia Britannica"). Gradually, the young Henry grew, interest in science and culture. By mastering the extensive knowledge he came as a result of persistent self-employment. Just a few years he studied at the Albany Academy, by his own admission, he was "largely self-taught". It is unlikely that he is in those years would have dreamed that almost half a century later would be elected president of the National Academy of America.

In 1819, Mr.. Henry was admitted to the Albany Academy (the so-called at the time secondary education of high type). On poverty, he was released from tuition fees. At the Academy, considerable attention was paid to the study of mathematics and science education. Joseph was carried away in mathematics and physics, and, having studied for three years, was admitted to the syllabaries Institute. And in 1826. he chose to contest a teacher of mathematics and physics. During one of the research-related travel, he visited the well-known in the United States Military Academy, where he first saw the experience of Oersted, who discovered in 1819, Mr.. deviation of the magnetic needle current flowing through a wire. And in one of the shops of New York he became acquainted with the method of manufacturing a horseshoe magnet. It is unlikely that he then could have predicted that his later work in the field of electromagnetism, he became known not only in America but also in Europe.

. Soon, Henry was elected to the post of Professor of Mathematics and Physics Institute (also known as Albany Academy of Sciences).

. Getting Started with the writings of Henry Oersted and Ampere caused him great interest in electromagnetic phenomena
. Since 1826. he begins a systematic study to understand the mysteries of electricity. He became the only American scientist of the first half of the XIX century., Whose works in this area included in the treasury of science.

First he has devoted his research establishment electromagnets. He managed to make mnogovitkovye electromagnets, as well as mnogokatushechnye coils, which modify the number of coils and circuit connections to the galvanic battery. He created a unique electromagnets with a lifting capacity up to 325 kg with its own weight of the magnet 10 kg. Until now, the Smithsonian Institution in Washington kept Henry's electromagnet for Yale College with a pulling force of up to 100 kg. Many of Henry's electromagnets used in industry, in particular for the separation of iron ore. Trudy Henry in this area have received worldwide recognition and appreciation of Faraday and Jacobi.

Another area of application of talent, Henry became the telecommunications. He started to create an electromagnetic device capable of transmitting information with the speed of thought. Such a device he demonstrated in a large auditorium Albany Academy.

. Henry proved that the current battery "may bring a magnetic field in the solenoid, located at the distance, and create in it the mechanical forces: using this method can ensure the transfer of signals"
. Immediately designing Telegraphs Henry does not work, but knows that he assisted one of the inventors of telegraphy. Morse, who repeatedly came to Henry to Princeton to create a device. We note in passing that one of the instruments designed by Henry for transmission, was the first electric bell. J. Henry is considered one of the pioneers who laid the foundations of the theory of electromagnetic waves.

In 1842, Mr.. Henry the first of the physicists found that when the spark discharge of the Leyden jar (condenser) there are electromagnetic waves, which he called "waves of electricity, capable of a considerable distance magnetize steel needles. He gave a detailed description of the open electrical oscillations and suggested ways of excitation. Practically it was created first oscillator. In 1847, Mr.. findings were confirmed by Henry G. Helmholtz. Renowned writer Mitchell Wilson, in his book "American scientists and inventors" (M., . "Knowledge", . 1963) wrote, . Henry: beat Hertz, . finding, . that "needle, . were in the basement of the building, . magnetized by an electric spark, . received on the second floor ",
. Recall that T. Hertz (1857-1894) for the first time in 1887, Mr.. experimentally proved the existence of electromagnetic waves. Opening Henry deservedly was rated only a half-century later, at the dawn of radio engineering.

Henry made another important contribution to the development of electrical engineering and telecommunications. In June, 1832. He discovered the phenomenon of electromagnetic induction, nine months after Faraday's experiments in distant London, where he is, of course, knew nothing. For many years engaged in the manufacture of powerful electromagnets, Henry received the "electric spark from an electromagnet, and soon in an American scientific journal was placed his article" On receipt of electrical currents and sparks from magnetism ". Unlike Faraday, who began his experiments with the induction of electric currents, using solenoids, Henry immediately suggested the use of electromagnets. On the discovery of Faraday, he learned only in autumn 1832. I was disappointed that did not publish its story before, but stressed that he "managed to get the electrical effects in a way that differs from the method applied by Mr. Faraday". It is interesting to note, . Henry to avoid any influence on the battery galvanometer, . indicates the appearance of induction currents, . placed him at a distance of 12 m from the electromagnet, . and, . watching the arrow galvanometer, . asked his assistant on his signal to enable and disable the electromagnet from the battery.,

. In 1834-1838 he
. Henry discovered the phenomenon of self-induction and mutual induction. The inductor, set up Henry, stored in a well-known Princeton Institute, which he was a professor since 1832, Mr.. In 1835, Mr.. Henry invented the electromagnetic relays and circuit the battery, suitable for long-distance telegraphy.

In 1836, Mr.. he constructed a motor with oscillating motion of the electromagnet.

At the end of life, Henry was recognized as the leader of American physicists, and in 1868. He was elected President of the American Academy of Sciences. Despite the enormous contribution to science, Henry remained a very humble man. He wrote: ": I do not molested pay for their works, content with a happy mind, that my work complemented the sum of human knowledge."

Joseph Henry died May 13, 1878, he was buried at the cemetery in the suburbs of Washington. In 1883, Mr.. in front of the Smithsonian Institution, he was a monument. His statue stands in the Main Reading Room Library of Congress. The merits of Henry facing humanity are immortalized in the 1893. in electrical engineering congress in Chicago, where the unit of inductance was named "Henry."