Posted by admin | Posted in Uncategorized | Posted on 30-04-2010
Tags: andrews, henry, joe, joseph, joseph henry, joseph henry burgess, joseph henry green, joseph henry press, joseph henry sharp, silentvirus
Joseph Henry
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The Invention of the Telephone
The history of the telephone, from its invention to its present state of perfection, is interesting in the extreme, and affords a striking example of the fact that great inventions are almost invariably the result of long and careful study on the part of many workers, rather than the sudden inspiration of a single genius.
These steps were made in logical order, the knowledge contributed by each investigator making possible a deeper insight into the subject on the part of his successors.
The history of the knowledge of electromagnetism begins with July 20, 1820, and with this date very properly begins the history of the electric telephone. On that day Oersted, a professor in the University of Copenhagen, discovered that a magnetic needle tends to place itself at right angles to a wire carrying a current of electricity. Ampere immediately took up the subject, and in a very short time disclosed the laws upon which present electromagnetic theory is based.
In the following year Arago and Davy discovered that if a current be caused to flow through an insulated wire wrapped about a rod of steel the latter would exhibit magnetic properties. It was William Sturgeon, however, who in 1825 made an electromagnetas we know it today, and called it by that name. Joseph Henry also made his classic experiments on the electromagnet. Henry showed how to build a magnet capable of being operated over a great length of wire, a most important step.
In 1831 Faraday and Henry, independently, discovered the converse of these laws of electromagnetism that if the intensity of a magnetic field inclosed by a conductor be in anywise changed, a current of electricity will flow in the conductor. This current will flow only while such change is taking place, and its strength will depend directly on the rate of the change.
These two laws concerning the transformation of electric energy into magnetic, and its converse, the transformation of magnetic energy into electric, are certainly the most important in the field of telephony.
In 1837 Professor Page of Salem, Mass., discovered that a rod of iron, suddenly magnetized or demagnetized, would emit certain sounds due to a molecular rearrangement caused by the changing magnetic conditions. This phenomenon is known as " Page's effect."
In 1854 a Frenchman, Charles Bourseul, predicted the transmission of speech, and outlined a method correct save in one particular, but for which error one following his directions could have produced a speaking telephone. His words at this date seem almost prophetic:
"I have asked myself, for example, if the spoken word itself could not be transmitted by electricity; in a word, if what was spoken in Vienna may not be heard in Paris?"
Philip Reis, a German inventor, constructed what he called a telephone in 1861, following implicitly the path outlined by Bourseul.
Reis' telephone could be depended upon to transmit only musical sounds. The question as to whether it actually did transmit speech has been the subject of much discussion, but if it did this at all it was very imperfectly.
For the next fifteen years no apparent advance was made in the art of telephony, although several inventors gave it their attention.
In 1876 Professor Alexander Graham Bell and Professor Elisha Gray almost simultaneously invented successful speaking telephones. Gray was one of the principal claimants for the honor of being the first inventor of the telephone, but Bell apparently established his right to it, and also reaped the profit, for, after long litigation, the United States Patent Office and the courts awarded the priority to him instead of Gray.
About the Author
Malcolm Blake has written several articles relating to the telephone and telephone related services. Read his texts on reverse 411 services and reverse number look up sites.
How is my fantasy football team?
QB= Palmer, Kitna, Bulger
RB= LT, Steven Jackson, Frank Gore, Laurence Maroney, Joseph Addai, Travis Henry
WR= Tory Holt, Marvin Harrison, T.J. Houshmandzadeh, Larry Fitzgerald, Anquan Boldin
TE= Chris Cooley
Kicker= Wilkens
Defence= New England
only 9 people in my leauge though, so everyone got okay people.
how did you get like the best people in the league that early all your running backs are supposed to go in the first round
its beast
100 out of 100
rate my team its not as good but i am in a 10 person league with people taking kickers by the 5 round and taking matt hassle back in the 4 round retards
rate my team
