Telegraph, electric

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Date: Apr. 30, 2006
Publisher: Gale
Document Type: Topic overview
Length: 1,275 words
Lexile Measure: 1200L

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The need to communicate rapidly over long distances became critical once the Western world became heavily industrialized and urbanized. Visual telegraphy systems such as the semaphore had insuperable physical and speed limitations. Advances in the science of electricity permitted the crucial breakthrough, finally making it possible to send messages via electrical impulses over long distances through wires.

Experimenters began investigating the possibility of sending messages alphabetically by electric current during the early 1700s. As early as 1727, an experimenter in London managed to send an electrical impulse one sixth of a mile along thread. A writer identified only as C.M. in an issue of Scots Magazine of 1753 described a static-electricity telegraph that would spell out messages over a bundle of 26 wires, one for each letter of the alphabet. Claude Chappe (1763-1805), developer of the semaphore, experimented with a synchronized clockwork electric telegraph in 1790, and a system using this principle was developed by the Englishman Francis Ronalds (1788-1873) in 1816.

It was Chappe who coined the term "telegraph" (for his mechanical-visual semaphore), from the Greek tele, "far," and graphien, "to write." The practical development of electrical telegraphy was made possible by the invention of the electric battery, or voltaic pile, by Alessandro Volta in 1800. A steady, low-pressure form of electricity was now available. In 1804, Francisco Salva, who had earlier developed a static-electricity telegraph, now devised a battery-powered system that could send messages a short distance over wire. S. T. von Sömmering (1755-1830) demonstrated a similar device in 1809 in Germany, but its many wires made this telegraph impractical.

The next crucial step was the 1819 discovery by Hans Christian Oersted (1777-1851) of Denmark that a magnetic needle was deflected by an electric current passing by it. The Frenchman André Ampère (1775-1836) suggested using the deflection of the needle for an electric telegraph. Baron Schilling, a Russian diplomat stationed in Germany, who had seen a demonstration of von Sömmering's device in 1810, followed up on the magnetic-needle idea. By 1832, Schilling had designed an electromagnetic needle telegraph with an alarm that required significantly fewer wires because the letters of the alphabet were transmitted by a code. The German Carl-August von Steinheil (1801-1870) developed a single-circuit needle telegraph in 1827. None of these systems, however, was put into practical commercial use.

That final development was the accomplishment of two Englishmen, William F. Cooke (1806-1879) and Charles Wheatstone, and an American, Samuel Morse. Cooke and Wheatstone formed a partnership and in 1837 patented a five-wire, five-needle telegraph. Electric current moved magnetized needles, which pointed singly or in pairs to a background panel imprinted with letters and numerals. This system was demonstrated on a short line between Euston and Camden in London in 1837. It was then installed for use in 1838 by the Great Western Railway Company on its line between Paddington (in London) and West Drayton, about 13 miles away. The system was extended to Slough, about 18 miles away, in 1842. Cooke and Wheatstone simplified their telegraph to a two-needle design in 1842 and patented a single-needle instrument in 1845. While these telegraph lines were very successful, they attracted little public attention until 1845, when a suspected murderer was spotted boarding a train to London. A message telegraphed to the destination station of Paddington resulted in the man's arrest (he was later convicted and executed). This created much public excitement about the possibilities of telegraphy.

In the United States, the well-known American artist Morse had become intensely interested in 1832 in developing a way to transmit messages via electricity. His first crude device, built in 1835, consisted of a typesetting sender that made and broke an electric circuit, transmitting a coded message to an electromagnetic receiver that recorded the message as dots and dashes on a moving tape. Morse substituted a simple operator key to open and close the circuit in 1837. Since Morse had no background in science, he was stymied by technical problems, especially insufficient current in his battery and electromagnet. Chemistry professor Leonard Gale stepped in with valuable assistance in 1836, and also introduced Morse to Joseph Henry and his work on electromagnets. Henry had actually constructed a working electromagnetic telegraph, or relay, in 1831, and shared his knowlege with Morse.

Using what he now knew, Morse made one of the greatest practical advances in the telegraph. He designed a relay system using a series of electromagnets to open and close circuits along the telegraph wire, which kept the current strong enough to travel long distances. Morse demonstrated his telegraph in 1837. In 1838, he took on a partner, Alfred Vail, who brought mechanical expertise and his father's financial backing to Morse's enterprise. Vail made many improvements to the telegraph's design and helped refine the message-transmitting system into what became known as the Morse code. In 1843 the partners were granted $30,000 (worth almost $600,000 in 2005 dollars) by Congress to build an experimental telegraph line between Baltimore, Maryland, and Washington, D.C. Initial attempts to bury the line met with failure due to inadequate insulation. Young Ezra Cornell, who had invented a plow to bury the cable, suggested instead stringing it overhead.

Successful installation of the line was dramatically demonstrated by Morse on May 24, 1844, when he sent the famous message "What hath God wrought!" from the Supreme Court room in the Capitol to a waiting Vail in Baltimore. After this, telegraph lines proliferated rapidly across the United States. The telegraph became the standard way of communicating within cities until the widespread availability of the telephone around 1880. Many competing telegraph companies were formed amid contentious litigation over the Morse patents. Mergers soon consolidated these disparate businesses, with Western Union Telegraph Company, the largest, forming in 1856. By 1861, a telegraph line ran across the continent, and by 1866 it was possible to send messages across the Atlantic via a submarine cable, installed after numerous failures and herculean effort.

Refinements were continually made. The Morse system's receiver replaced inked messages with a simple "sounder" in 1856; operators could "read" the clicks they heard and transcribe them into written messages. Improved insulating methods, especially the use of India rubber and gutta-percha (a rubberlike substance derived from the tropical gutta-percha tree), reduced overhead as well as underground line failure. A duplex circuit developed in Germany allowed messages to travel simultaneously in opposite directions along a single line. Thomas Alva Edison designed a quadruplex in 1874, making two messages in each direction possible. In 1872, Jean-Maurice Baudot invented a multiplex line that could handle five messages at once.

Soon after telegraph systems came into use, attempts were made to develop printing telegraphs to eliminate the need for skilled operators and to improve reception time. Vail invented a printing system in 1837; Alexander Bain (1818-1903) designed one in 1843, followed by Royal House (1814-1895) in 1846. Wheatstone developed a model in 1841, as did fellow Englishman John W. Brett (1805-1863) in 1846. David Hughes (1831-1900) of Kentucky designed a continuous-movement printing system in 1855 which successfully synchronized sending and receiving apparatus. With improvements, the Hughes machine became the industry standard. In 1878 the typewriter was adapted for use as a telegraphic printer.

The impact of worldwide telegraphy was great. Instant communication over long distances, never before possible, became commonplace. Journalism was transformed; far-away events were reported almost as soon as they occurred, instead of weeks or months later. Large, far-flung corporate structures became feasible. The United States could be treated as one large national market. Also, individuals, through news reports or personal communication, felt more closely connected with people and places in far distant parts of the continent and globe.

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Gale Document Number: GALE|CV1647500793