what is telegraph?

Answer 1

The electrical telegraph is a telegraph that uses electric signals. The electromagnetic telegraph is a device for transmission of written messages without physical transport of letters over wire. The first telegraphs were built independently in the apartment of Russian inventor Pavel Shilling in St.Petersburg, in 1832 where it was demonstrated to wide public. Another electromagnetic telegraph was used publicly by Carl Friedrich Gauss and Wilhelm Weber in Göttingen's university in 1833.

click here:http://en.wikipedia.org/wiki/Telegraph#History

Answer 2

The electrical telegraph is a telegraph that uses electric signals. The electromagnetic telegraph is a device for transmission of written messages without physical transport of letters over wire. The first telegraphs were built independently in the apartment of Russian inventor Pavel Shilling in St.Petersburg, in 1832 where it was demonstrated to wide public. Another electromagnetic telegraph was used publicly by Carl Friedrich Gauss and Wilhelm Weber in Göttingen's university in 1833

Answer 3

The electrical telegraph is a telegraph that uses electric signals. The electromagnetic telegraph is a device for transmission of written messages without physical transport of letters over wire. The first telegraphs were built independently in the apartment of Russian inventor Pavel Shilling in St.Petersburg, in 1832 where it was demonstrated to wide public. Another electromagnetic telegraph was used publicly by Carl Friedrich Gauss and Wilhelm Weber in Göttingen's university in 1833.

In 1795 Francisco de Salva offered an electrostatical telegraph. Telegraphy based on static electricity was impractical because of the high voltages required. Alessandro Volta invented the Voltaic Pile in 1800, allowing a continuous current for experimentation. Samuel T. Soemmering constructed his electrochemical telegraph in 1809. Hans Christian Ørsted discovered in 1820 that an electric current produces a magnetic field which will deflect a compass needle. Also in 1820, Johann Schweigger invented the galvanometer, with a coil of wire around a compass, which could be used as a sensitive indicator for electric current. In 1821, André-Marie Ampère suggested that telegraphy could be done by a system of galvanometers, with one wire per galvanometer to indicate each letter, and said he had experimented successfully with such a system. In 1824, Peter Barlow said that such a system only worked to a distance of about 200 feet, and so was impractical. William Sturgeon in 1825 invented the electromagnet, with a single winding of uninsulated wire on a piece of varnished iron, which increased the magnetic force produced by electric current. In 1828, Joseph Henry improved the electromagnet by placing on it several windings of insulated wire, creating a much more powerful electromagnet which could operate a telegraph through the high resistance of long telegraph wires. An electromagnetic telegraph was created by Baron Schilling in 1832. Carl Friedrich Gauß and Wilhelm Weber built an electromagnetic telegraph in 1833 in Göttingen. In 1835 Joseph Henry invented the relay, by which a weak current over long wires could operate a powerful local electromagnet. [1] [2]

The first commercial electrical telegraph was constructed by Sir Charles Wheatstone and Sir William Fothergill Cooke and entered use on the Great Western Railway. Wheatstone and Cooke patented it in May 1837 as an alarm system. It ran for 13 miles from Paddington station to West Drayton and came into operation on April 9, 1839. It was patented in the Uk in 1837. In early 1845, John Tawell was apprehended following the use of a needle telegraph message from Slough to Paddington on January 1, 1845. This is thought to be the first use of the telegraph to catch a murderer. The message was:

A murder has just been committed at Salt Hill and the suspected murderer was seen to take a first class ticket to London by the train that left Slough at 7.42pm. He is in the garb of a Kwaker with a brown great coat on which reaches his feet. He is in the last compartment of the second first-class carriage
The reason for the misspelling of 'Quaker' was that the British system did not support the letter Q.

An electrical telegraph was independently developed in the United States by Dr. David Alter in 1836, and developed and patented in the United States in 1837 by Samuel Morse.

Answer 4

A communications system that transmits and receives simple unmodulated electric impulses, especially one in which the transmission and reception stations are directly connected by wires.