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Titel: Heroes of the Telegraph
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Alle Rechte vorbehalten.
Author Of 'Electricity And Its Uses,' Pioneers Of Electricity,' 'The Wire And The Wave'; And Joint Author Of 'Munro And Jamieson's Pocket-Book Of Electrical Rules And Tables.'
(Note: All accents etc. have been omitted. Italics have been converted to capital letters. The British 'pound' sign has been written as 'L'. Footnotes have been placed in square brackets at the place in the text where a suffix originally indicated their existence.)
The present work is in some respects a sequel to the PIONEERS OF ELECTRICITY, and it deals with the lives and principal achievements of those distinguished men to whom we are indebted for the introduction of the electric telegraph and telephone, as well as other marvels of electric science.
CHAPTER I. THE ORIGIN OF THE TELEGRAPH.
CHAPTER II. CHARLES WHEATSTONE.
CHAPTER III. SAMUEL MORSE.
CHAPTER IV. SIR WILLIAM THOMSON.
CHAPTER V. CHARLES WILLIAM SIEMENS.
CHAPTER VI. FLEEMING JENKIN.
CHAPTER VII. JOHANN PHILIPP REIS.
CHAPTER VIII. GRAHAM BELL.
CHAPTER IX. THOMAS ALVA EDISON.
CHAPTER X. DAVID EDWIN HUGHES.
I. CHARLES FERDINAND GAUSS.
II. WILLIAM EDWARD WEBER.
III. SIR WILLIAM FOTHERGILL COOKE.
IV. ALEXANDER BAIN.
V. DR. WERNER SIEMENS.
VI. LATIMER CLARK.
VII. COUNT DU MONCEL.
VIII. ELISHA GRAY.
The history of an invention, whether of science or art, may be compared to the growth of an organism such as a tree. The wind, or the random visit of a bee, unites the pollen in the flower, the green fruit forms and ripens to the perfect seed, which, on being planted in congenial soil, takes root and flourishes. Even so from the chance combination of two facts in the human mind, a crude idea springs, and after maturing into a feasible plan is put in practice under favourable conditions, and so develops. These processes are both subject to a thousand accidents which are inimical to their achievement. Especially is this the case when their object is to produce a novel species, or a new and great invention like the telegraph. It is then a question of raising, not one seedling, but many, and modifying these in the lapse of time.
Similarly the telegraph is not to be regarded as the work of any one mind, but of many, and during a long course of years. Because at length the final seedling is obtained, are we to overlook the antecedent varieties from which it was produced, and without which it could not have existed? Because one inventor at last succeeds in putting the telegraph in operation, are we to neglect his predecessors, whose attempts and failures were the steps by which he mounted to success? All who have extended our knowledge of electricity, or devised a telegraph, and familiarised the public mind with the advantages of it, are deserving of our praise and gratitude, as well as he who has entered into their labours, and by genius and perseverance won the honours of being the first to introduce it.
Let us, therefore, trace in a rapid manner the history of the electric telegraph from the earliest times.
The sources of a river are lost in the clouds of the mountain, but it is usual to derive its waters from the lakes or springs which are its fountain-head. In the same way the origins of our knowledge of electricity and magnetism are lost in the mists of antiquity, but there are two facts which have come to be regarded as the starting-points of the science. It was known to the ancients at least 600 years before Christ, that a piece of amber when excited by rubbing would attract straws, and that a lump of lodestone had the property of drawing iron. Both facts were probably ascertained by chance. Humboldt informs us that he saw an Indian child of the Orinoco rubbing the seed of a trailing plant to make it attract the wild cotton; and, perhaps, a prehistoric tribesman of the Baltic or the plains of Sicily found in the yellow stone he had polished the mysterious power of collecting dust. A Greek legend tells us that the lodestone was discovered by Magnes, a shepherd who found his crook attracted by the rock.
However this may be, we are told that Thales of Miletus attributed the attractive properties of the amber and the lodestone to a soul within them. The name Electricity is derived from ELEKTRON, the Greek for amber, and Magnetism from Magnes, the name of the shepherd, or, more likely, from the city of Magnesia, in Lydia, where the stone occurred.
These properties of amber and lodestone appear to have been widely known. The Persian name for amber is KAHRUBA, attractor of straws, and that for lodestone AHANG-RUBA attractor of iron. In the old Persian romance, THE LOVES OF MAJNOON AND LEILA, the lover sings—
The Chinese philosopher, Kuopho, who flourished in the fourth century, writes that, 'the attraction of a magnet for iron is like that of amber for the smallest grain of mustard seed. It is like a breath of wind which mysteriously penetrates through both, and communicates itself with the speed of an arrow.' [Lodestone was probably known in China before the Christian era.] Other electrical effects were also observed by the ancients. Classical writers, as Homer, Caesar, and Plutarch, speak of flames on the points of javelins and the tips of masts. They regarded them as manifestations of the Deity, as did the soldiers of the Mahdi lately in the Soudan. It is recorded of Servius Tullus, the sixth king of Rome, that his hair emitted sparks on being combed; and that sparks came from the body of Walimer, a Gothic chief, who lived in the year 415 A.D.
During the dark ages the mystical virtues of the lodestone drew more attention than those of the more precious amber, and interesting experiments were made with it. The Romans knew that it could attract iron at some distance through an intervening fence of wood, brass, or stone. One of their experiments was to float a needle on a piece of cork, and make it follow a lodestone held in the hand. This arrangement was perhaps copied from the compass of the Phoenician sailors, who buoyed a lodestone and observed it set towards the north. There is reason to believe that the magnet was employed by the priests of the Oracle in answering questions. We are told that the Emperor Valerius, while at Antioch in 370 A.D., was shown a floating needle which pointed to the letters of the alphabet when guided by the directive force of a lodestone. It was also believed that this effect might be produced although a stone wall intervened, so that a person outside a house or prison might convey intelligence to another inside.
This idea was perhaps the basis of the sympathetic telegraph of the Middle Ages, which is first described in the MAGIAE NATURALIS of John Baptista Porta, published at Naples in 1558. It was supposed by Porta and others after him that two similar needles touched by the same lodestone were sympathetic, so that, although far apart, if both were freely balanced, a movement of one was imitated by the other. By encircling each balanced needle with an alphabet, the sympathetic telegraph was obtained. Although based on error, and opposed by Cabeus and others, this fascinating notion continued to crop up even to the days of Addison. It was a prophetic shadow of the coming invention. In the SCEPSIS SCIENTIFICA, published in 1665, Joseph Glanvil wrote, 'to confer at the distance of the Indies by sympathetic conveyances may be as usual to future times as to us in literary correspondence.' [The Rosicrucians also believed that if two persons transplanted pieces of their flesh into each other, and tattooed the grafts with letters, a sympathetic telegraph could be established by pricking the letters.]
Dr. Gilbert, physician to Queen Elizabeth, by his systematic researches, discovered the magnetism of the earth, and laid the foundations of the modern science of electricity and magnetism. Otto von Guericke, burgomaster of Magdeburg, invented the electrical machine for generating large quantities of the electric fire. Stephen Gray, a pensioner of the Charterhouse, conveyed the fire to a distance along a line of pack thread, and showed that some bodies conducted electricity, while others insulated it. Dufay proved that there were two qualities of electricity, now called positive and negative, and that each kind repelled the like, but attracted the unlike. Von Kleist, a cathedral dean of Kamm, in Pomerania, or at all events Cuneus, a burgher, and Muschenbroek, a professor of Leyden, discovered the Leyden jar for holding a charge of electricity; and Franklin demonstrated the identity of electricity and lightning.
The charge from a Leyden jar was frequently sent through a chain of persons clasping hands, or a length of wire with the earth as part of the circuit. This experiment was made by Joseph Franz, of Vienna, in 1746, and Dr. Watson, of London, in 1747; while Franklin ignited spirits by a spark which had been sent across the Schuylkill river by the same means. But none of these men seem to have grasped the idea of employing the fleet fire as a telegraph.
The first suggestion of an electric telegraph on record is that published by one 'C. M.' in the Scots Magazine for February 17, 1753. The device consisted in running a number of insulated wires between two places, one for each letter of the alphabet. The wires were to be charged with electricity from a machine one at a time, according to the letter it represented. At its far end the charged wire was to attract a disc of paper marked with the corresponding letter, and so the message would be spelt. 'C. M.' also suggested the first acoustic telegraph, for he proposed to have a set of bells instead of the letters, each of a different tone, and to be struck by the spark from its charged wire.
The identity of 'C. M.,' who dated his letter from Renfrew, has not been established beyond a doubt. There is a tradition of a clever man living in Renfrew at that time, and afterwards in Paisley, who could 'licht a room wi' coal reek (smoke), and mak' lichtnin' speak and write upon the wa'.' By some he was thought to be a certain Charles Marshall, from Aberdeen; but it seems likelier that he was a Charles Morrison, of Greenock, who was trained as a surgeon, and became connected with the tobacco trade of Glasgow. In Renfrew he was regarded as a kind of wizard, and he is said to have emigrated to Virginia, where he died.
In the latter half of the eighteenth century, many other suggestions of telegraphs based on the known properties of the electric fire were published; for example, by Joseph Bozolus, a Jesuit lecturer of Rome, in 1767; by Odier, a Geneva physicist, in 1773, who states in a letter to a lady, that he conceived the idea on hearing a casual remark, while dining at Sir John Pringle's, with Franklin, Priestley, and other great geniuses. 'I shall amuse you, perhaps, in telling you,' he says,'that I have in my head certain experiments by which to enter into conversation with the Emperor of Mogol or of China, the English, the French, or any other people of Europe... You may intercommunicate all that you wish at a distance of four or five thousands leagues in less than half an hour. Will that suffice you for glory?'
George Louis Lesage, in 1782, proposed a plan similar to 'C. M.'s,' using underground wires. An anonymous correspondent of the JOURNAL DE PARIS for May 30, 1782, suggested an alarm bell to call attention to the message. Lomond, of Paris, devised a telegraph with only one wire; the signals to be read by the peculiar movements of an attracted pith-ball, and Arthur Young witnessed his plan in action, as recorded in his diary. M. Chappe, the inventor of the semaphore, tried about the year 1790 to introduce a synchronous electric telegraph, and failed.
Don Francisco Salva y Campillo, of Barcelona, in 1795, proposed to make a telegraph between Barcelona and Mataro, either overhead or underground, and he remarks of the wires, 'at the bottom of the sea their bed would be ready made, and it would be an extraordinary casualty that should disturb them.' In Salva's telegraph, the signals were to be made by illuminating letters of tinfoil with the spark. Volta's great invention of the pile in 1800 furnished a new source of electricity, better adapted for the telegraph, and Salva was apparently the first to recognise this, for, in the same year, he proposed to use it and interpret the signals by the twitching of a frog's limb, or the decomposition of water.
In 1802, Jean Alexandre, a reputed natural son of Jean Jacques Rousseau, brought out a TELEGRAPHE INTIME, or secret telegraph, which appears to have been a step-by-step apparatus. The inventor concealed its mode of working, but it was believed to be electrical, and there was a needle which stopped at various points on a dial. Alexandre stated that he had found out a strange matter or power which was, perhaps generally diffused, and formed in some sort the soul of the universe. He endeavoured to bring his invention under the eye of the First Consul, but Napoleon referred the matter to Delambre, and would not see it. Alexandre was born at Paris, and served as a carver and gilder at Poictiers; then sang in the churches till the Revolution suppressed this means of livelihood. He rose to influence as a Commissary-general, then retired from the army and became an inventor. His name is associated with a method of steering balloons, and a filter for supplying Bordeaux with water from the Garonne. But neither of these plans appear to have been put in practice, and he died at Angouleme, leaving his widow in extreme poverty.
Sommering, a distinguished Prussian anatomist, in 1809 brought out a telegraph worked by a voltaic battery, and making signals by decomposing water. Two years later it was greatly simplified by Schweigger, of Halle; and there is reason to believe that but for the discovery of electro-magnetism by Oersted, in 1824 the chemical telegraph would have come into practical use.
In 1806, Ralph Wedgwood submitted a telegraph based on frictional electricity to the Admiralty, but was told that the semaphore was sufficient for the country. In a pamphlet he suggested the establishment of a telegraph system with public offices in different centres. Francis Ronalds, in 1816, brought a similar telegraph of his invention to the notice of the Admiralty, and was politely informed that 'telegraphs of any kind are now wholly unnecessary.'
In 1826-7, Harrison Gray Dyar, of New York, devised a telegraph in which the spark was made to stain the signals on moist litmus paper by decomposing nitric acid; but he had to abandon his experiments in Long Island and fly the country, because of a writ which charged him with a conspiracy for carrying on secret communication. In 1830 Hubert Recy published an account of a system of Teletatodydaxie, by which the electric spark was to ignite alcohol and indicate the signals of a code.
But spark or frictional electric telegraphs were destined to give way to those actuated by the voltaic current, as the chemical mode of signalling was superseded by the electro-magnet. In 1820 the separate courses of electric and magnetic science were united by the connecting discovery of Oersted, who found that a wire conveying a current had the power of moving a compass-needle to one side or the other according to the direction of the current.
La Place, the illustrious mathematician, at once saw that this fact could be utilised as a telegraph, and Ampere, acting on his suggestion, published a feasible plan. Before the year was out, Schweigger, of Halle, multiplied the influence of the current on the needle by coiling the wire about it. Ten years later, Ritchie improved on Ampere's method, and exhibited a model at the Royal Institution, London. About the same time, Baron Pawel Schilling, a Russian nobleman, still further modified it, and the Emperor Nicholas decreed the erection of a line from Cronstadt to St. Petersburg, with a cable in the Gulf of Finland but Schilling died in 1837, and the project was never realised.
In 1833-5 Professors Gauss and Weber constructed a telegraph between the physical cabinet and the Observatory of the University of Gottingen. At first they used the voltaic pile, but abandoned it in favour of Faraday's recent discovery that electricity could be generated in a wire by the motion of a magnet. The magnetic key with which the message was sent Produced by its action an electric current which, after traversing the line, passed through a coil and deflected a suspended magnet to the right or left, according to the direction of the current. A mirror attached to the suspension magnified the movement of the needle, and indicated the signals after the manner of the Thomson mirror galvanometer. This telegraph, which was large and clumsy, was nevertheless used not only for scientific, but for general correspondence. Steinheil, of Munich, simplified it, and added an alarm in the form of a bell.
In 1836, Steinheil also devised a recording telegraph, in which the movable needles indicated the message by marking dots and dashes with printer's ink on a ribbon of travelling paper, according to an artificial code in which the fewest signs were given to the commonest letters in the German language. With this apparatus the message was registered at the rate of six words a minute. The early experimenters, as we have seen, especially Salva, had utilised the ground as the return part of the circuit; and Salva had proposed to use it on his telegraph, but Steinheil was the first to demonstrate its practical value. In trying, on the suggestion of Gauss, to employ the rails of the Nurenberg to Furth railway as the conducting line for a telegraph in the year 1838, he found they would not serve; but the failure led him to employ the earth as the return half of the circuit.
In 1837, Professor Stratingh, of Groninque, Holland, devised a telegraph in which the signals were made by electro-magnets actuating the hammers of two gongs or bells of different tone; and M. Amyot invented an automatic sending key in the nature of a musical box. From 1837-8, Edward Davy, a Devonshire surgeon, exhibited a needle telegraph in London, and proposed one based on the discovery of Arago, that a piece of soft iron is temporarily magnetised by the passage of an electric current through a coil surrounding it. This principle was further applied by Morse in his electro-magnetic printing telegraph. Davy was a prolific inventor, and also sketched out a telegraph in which the gases evolved from water which was decomposed by the current actuated a recording pen. But his most valuable discovery was the 'relay,' that is to say, an auxiliary device by which a current too feeble to indicate the signals could call into play a local battery strong enough to make them. Davy was in a fair way of becoming one of the fathers of the working telegraph, when his private affairs obliged him to emigrate to Australia, and leave the course open to Cooke and Wheatstone.
The electric telegraph, like the steam-engine and the railway, was a gradual development due to the experiments and devices of a long train of thinkers. In such a case he who crowns the work, making it serviceable to his fellow-men, not only wins the pecuniary prize, but is likely to be hailed and celebrated as the chief, if not the sole inventor, although in a scientific sense the improvement he has made is perhaps less than that of some ingenious and forgotten forerunner. He who advances the work from the phase of a promising idea, to that of a common boon, is entitled to our gratitude. But in honouring the keystone of the arch, as it were, let us acknowledge the substructure on which it rests, and keep in mind the entire bridge. Justice at least is due to those who have laboured without reward.
Sir William Fothergill Cooke and Sir Charles Wheatstone were the first to bring the electric telegraph into daily use. But we have selected Wheatstone as our hero, because he was eminent as a man of science, and chiefly instrumental in perfecting the apparatus. As James Watt is identified with the steam-engine, and George Stephenson with the railway, so is Wheatstone with the telegraph.
Charles Wheatstone was born near Gloucester, in February, 1802. His father was a music-seller in the town, who, four years later, removed to 128, Pall Mall, London, and became a teacher of the flute. He used to say, with not a little pride, that he had been engaged in assisting at the musical education of the Princess Charlotte. Charles, the second son, went to a village school, near Gloucester, and afterwards to several institutions in London. One of them was in Kennington, and kept by a Mrs. Castlemaine, who was astonished at his rapid progress. From another he ran away, but was captured at Windsor, not far from the theatre of his practical telegraph. As a boy he was very shy and sensitive, liking well to retire into an attic, without any other company than his own thoughts. When he was about fourteen years old he was apprenticed to his uncle and namesake, a maker and seller of musical instruments, at 436, Strand, London; but he showed little taste for handicraft or business, and loved better to study books. His father encouraged him in this, and finally took him out of the uncle's charge.
At the age of fifteen, Wheatstone translated French poetry, and wrote two songs, one of which was given to his uncle, who published it without knowing it as his nephew's composition. Some lines of his on the lyre became the motto of an engraving by Bartolozzi. Small for his age, but with a fine brow, and intelligent blue eyes, he often visited an old book-stall in the vicinity of Pall Mall, which was then a dilapidated and unpaved thoroughfare. Most of his pocket-money was spent in purchasing the books which had taken his fancy, whether fairy tales, history, or science. One day, to the surprise of the bookseller, he coveted a volume on the discoveries of Volta in electricity, but not having the price, he saved his pennies and secured the volume. It was written in French, and so he was obliged to save again, till he could buy a dictionary. Then he began to read the volume, and, with the help of his elder brother, William, to repeat the experiments described in it, with a home-made battery, in the scullery behind his father's house. In constructing the battery the boy philosophers ran short of money to procure the requisite copper-plates. They had only a few copper coins left. A happy thought occurred to Charles, who was the leading spirit in these researches, 'We must use the pennies themselves,' said he, and the battery was soon complete.
In September, 1821, Wheatstone brought himself into public notice by exhibiting the 'Enchanted Lyre,' or 'Aconcryptophone,' at a music-shop at Pall Mall and in the Adelaide Gallery. It consisted of a mimic lyre hung from the ceiling by a cord, and emitting the strains of several instruments—the piano, harp, and dulcimer. In reality it was a mere sounding box, and the cord was a steel rod that conveyed the vibrations of the music from the several instruments which were played out of sight and ear-shot. At this period Wheatstone made numerous experiments on sound and its transmission. Some of his results are preserved in Thomson's ANNALS OF PHILOSOPHY for 1823. He recognised that sound is propagated by waves or oscillations of the atmosphere, as light by undulations of the luminiferous ether. Water, and solid bodies, such as glass, or metal, or sonorous wood, convey the modulations with high velocity, and he conceived the plan of transmitting sound-signals, music, or speech to long distances by this means. He estimated that sound would travel 200 miles a second through solid rods, and proposed to telegraph from London to Edinburgh in this way. He even called his arrangement a 'telephone.' [Robert Hooke, in his MICROGRAPHIA, published in 1667, writes: 'I can assure the reader that I have, by the help of a distended wire, propagated the sound to a very considerable distance in an instant, or with as seemingly quick a motion as that of light.' Nor was it essential the wire should be straight; it might be bent into angles. This property is the basis of the mechanical or lover's telephone, said to have been known to the Chinese many centuries ago. Hooke also considered the possibility of finding a way to quicken our powers of hearing.] A writer in the REPOSITORY OF ARTS for September 1, 1821, in referring to the 'Enchanted Lyre,' beholds the prospect of an opera being performed at the King's Theatre, and enjoyed at the Hanover Square Rooms, or even at the Horns Tavern, Kennington. The vibrations are to travel through underground conductors, like to gas in pipes. 'And if music be capable of being thus conducted,' he observes,'perhaps the words of speech may be susceptible of the same means of propagation. The eloquence of counsel, the debates of Parliament, instead of being read the next day only,—But we shall lose ourselves in the pursuit of this curious subject.'
Besides transmitting sounds to a distance, Wheatstone devised a simple instrument for augmenting feeble sounds, to which he gave the name of 'Microphone.' It consisted of two slender rods, which conveyed the mechanical vibrations to both ears, and is quite different from the electrical microphone of Professor Hughes.
In 1823, his uncle, the musical instrument maker, died, and Wheatstone, with his elder brother, William, took over the business. Charles had no great liking for the commercial part, but his ingenuity found a vent in making improvements on the existing instruments, and in devising philosophical toys. At the end of six years he retired from the undertaking.
In 1827, Wheatstone introduced his 'kaleidoscope,' a device for rendering the vibrations of a sounding body apparent to the eye. It consists of a metal rod, carrying at its end a silvered bead, which reflects a 'spot' of light. As the rod vibrates the spot is seen to describe complicated figures in the air, like a spark whirled about in the darkness. His photometer was probably suggested by this appliance. It enables two lights to be compared by the relative brightness of their reflections in a silvered bead, which describes a narrow ellipse, so as to draw the spots into parallel lines.
In 1828, Wheatstone improved the German wind instrument, called the MUND HARMONICA, till it became the popular concertina, patented on June 19, 1829 The portable harmonium is another of his inventions, which gained a prize medal at the Great Exhibition of 1851. He also improved the speaking machine of De Kempelen, and endorsed the opinion of Sir David Brewster, that before the end of this century a singing and talking apparatus would be among the conquests of science.
In 1834, Wheatstone, who had won a name for himself, was appointed to the Chair of Experimental Physics in King's College, London, But his first course of lectures on Sound were a complete failure, owing to an invincible repugnance to public speaking, and a distrust of his powers in that direction. In the rostrum he was tongue-tied and incapable, sometimes turning his back on the audience and mumbling to the diagrams on the wall. In the laboratory he felt himself at home, and ever after confined his duties mostly to demonstration.
He achieved renown by a great experiment—the measurement of the velocity of electricity in a wire. His method was beautiful and ingenious. He cut the wire at the middle, to form a gap which a spark might leap across, and connected its ends to the poles of a Leyden jar filled with electricity. Three sparks were thus produced, one at either end of the wire, and another at the middle. He mounted a tiny mirror on the works of a watch, so that it revolved at a high velocity, and observed the reflections of his three sparks in it. The points of the wire were so arranged that if the sparks were instantaneous, their reflections would appear in one straight line; but the middle one was seen to lag behind the others, because it was an instant later. The electricity had taken a certain time to travel from the ends of the wire to the middle. This time was found by measuring the amount of lag, and comparing it with the known velocity of the mirror. Having got the time, he had only to compare that with the length of half the wire, and he found that the velocity of electricity was 288,000 miles a second.
Till then, many people had considered the electric discharge to be instantaneous; but it was afterwards found that its velocity depended on the nature of the conductor, its resistance, and its electro-static capacity. Faraday showed, for example, that its velocity in a submarine wire, coated with insulator and surrounded with water, is only 144,000 miles a second, or still less. Wheatstone's device of the revolving mirror was afterwards employed by Foucault and Fizeau to measure the velocity of light.
In 1835, at the Dublin meeting of the British Association, Wheatstone showed that when metals were volatilised in the electric spark, their light, examined through a prism, revealed certain rays which were characteristic of them. Thus the kind of metals which formed the sparking points could be determined by analysing the light of the spark. This suggestion has been of great service in spectrum analysis, and as applied by Bunsen, Kirchoff, and others, has led to the discovery of several new elements, such as rubidium and thallium, as well as increasing our knowledge of the heavenly bodies. Two years later, he called attention to the value of thermo-electricity as a mode of generating a current by means of heat, and since then a variety of thermo-piles have been invented, some of which have proved of considerable advantage.
Wheatstone abandoned his idea of transmitting intelligence by the mechanical vibration of rods, and took up the electric telegraph. In 1835 he lectured on the system of Baron Schilling, and declared that the means were already known by which an electric telegraph could be made of great service to the world. He made experiments with a plan of his own, and not only proposed to lay an experimental line across the Thames, but to establish it on the London and Birmingham Railway. Before these plans were carried out, however, he received a visit from Mr. Fothergill Cooke at his house in Conduit Street on February 27, 1837, which had an important influence on his future.
Mr. Cooke was an officer in the Madras army, who, being home on furlough, was attending some lectures on anatomy at the University of Heidelberg, where, on March 6, 1836, he witnessed a demonstration with the telegraph of Professor Moncke, and was so impressed with its importance, that he forsook his medical studies and devoted all his efforts to the work of introducing the telegraph. He returned to London soon after, and was able to exhibit a telegraph with three needles in January, 1837. Feeling his want of scientific knowledge, he consulted Faraday and Dr. Roget, the latter of whom sent him to Wheatstone.
At a second interview, Mr. Cooke told Wheatstone of his intention to bring out a working telegraph, and explained his method. Wheatstone, according to his own statement, remarked to Cooke that the method would not act, and produced his own experimental telegraph. Finally, Cooke proposed that they should enter into a partnership, but Wheatstone was at first reluctant to comply. He was a well-known man of science, and had meant to publish his results without seeking to make capital of them. Cooke, on the other hand, declared that his sole object was to make a fortune from the scheme. In May they agreed to join their forces, Wheatstone contributing the scientific, and Cooke the administrative talent. The deed of partnership was dated November 19, 1837. A joint patent was taken out for their inventions, including the five-needle telegraph of Wheatstone, and an alarm worked by a relay, in which the current, by dipping a needle into mercury, completed a local circuit, and released the detent of a clockwork.
The five-needle telegraph, which was mainly, if not entirely, due to Wheatstone, was similar to that of Schilling, and based on the principle enunciated by Ampere—that is to say, the current was sent into the line by completing the circuit of the battery with a make and break key, and at the other end it passed through a coil of wire surrounding a magnetic needle free to turn round its centre. According as one pole of the battery or the other was applied to the line by means of the key, the current deflected the needle to one side or the other. There were five separate circuits actuating five different needles. The latter were pivoted in rows across the middle of a dial shaped like a diamond, and having the letters of the alphabet arranged upon it in such a way that a letter was literally pointed out by the current deflecting two of the needles towards it.
An experimental line, with a sixth return wire, was run between the Euston terminus and Camden Town station of the London and North Western Railway on July 25, 1837. The actual distance was only one and a half mile, but spare wire had been inserted in the circuit to increase its length. It was late in the evening before the trial took place. Mr. Cooke was in charge at Camden Town, while Mr. Robert Stephenson and other gentlemen looked on; and Wheatstone sat at his instrument in a dingy little room, lit by a tallow candle, near the booking-office at Euston. Wheatstone sent the first message, to which Cooke replied, and 'never,' said Wheatstone, 'did I feel such a tumultuous sensation before, as when, all alone in the still room, I heard the needles click, and as I spelled the words, I felt all the magnitude of the invention pronounced to be practicable beyond cavil or dispute.'
In spite of this trial, however, the directors of the railway treated the 'new-fangled' invention with indifference, and requested its removal. In July, 1839, however, it was favoured by the Great Western Railway, and a line erected from the Paddington terminus to West Drayton station, a distance of thirteen miles. Part of the wire was laid underground at first, but subsequently all of it was raised on posts along the line. Their circuit was eventually extended to Slough in 1841, and was publicly exhibited at Paddington as a marvel of science, which could transmit fifty signals a distance of 280,000 miles in a minute. The price of admission was a shilling.
Notwithstanding its success, the public did not readily patronise the new invention until its utility was noised abroad by the clever capture of the murderer Tawell. Between six and seven o'clock one morning a woman named Sarah Hart was found dead in her home at Salt Hill, and a man had been observed to leave her house some time before. The police knew that she was visited from time to time by a Mr. John Tawell, from Berkhampstead, where he was much respected, and on inquiring and arriving at Slough, they found that a person answering his description had booked by a slow train for London, and entered a first-class carriage. The police telegraphed at once to Paddington, giving the particulars, and desiring his capture. 'He is in the garb of a Quaker,' ran the message, 'with a brown coat on, which reaches nearly to his feet.' There was no 'Q' in the alphabet of the five-needle instrument, and the clerk at Slough began to spell the word 'Quaker' with a 'kwa'; but when he had got so far he was interrupted by the clerk at Paddington, who asked him to 'repent.' The repetition fared no better, until a boy at Paddington suggested that Slough should be allowed to finish the word. 'Kwaker' was understood, and as soon as Tawell stepped out on the platform at Paddington he was 'shadowed' by a detective, who followed him into a New Road omnibus, and arrested him in a coffee tavern.
Tawell was tried for the murder of the woman, and astounding revelations were made as to his character. Transported in 1820 for the crime of forgery, he obtained a ticket-of-leave, and started as a chemist in Sydney, where he flourished, and after fifteen years left it a rich man. Returning to England, he married a Quaker lady as his second wife. He confessed to the murder of Sarah Hart, by prussic acid, his motive being a dread of their relations becoming known.
Tawell was executed, and the notoriety of the case brought the telegraph into repute. Its advantages as a rapid means of conveying intelligence and detecting criminals had been signally demonstrated, and it was soon adopted on a more extensive scale.
In 1845 Wheatstone introduced two improved forms of the apparatus, namely, the 'single' and the 'double' needle instruments, in which the signals were made by the successive deflections of the needles. Of these, the single-needle instrument, requiring only one wire, is still in use.
In 1841 a difference arose between Cooke and Wheatstone as to the share of each in the honour of inventing the telegraph. The question was submitted to the arbitration of the famous engineer, Marc Isambard Brunel, on behalf of Cooke, and Professor Daniell, of King's College, the inventor of the Daniell battery, on the part of Wheatstone. They awarded to Cooke the credit of having introduced the telegraph as a useful undertaking which promised to be of national importance, and to Wheatstone that of having by his researches prepared the public to receive it. They concluded with the words: 'It is to the united labours of two gentlemen so well qualified for mutual assistance that we must attribute the rapid progress which this important invention has made during five years since they have been associated.' The decision, however vague, pronounces the needle telegraph a joint production. If it was mainly invented by Wheatstone, it was chiefly introduced by Cooke. Their respective shares in the undertaking might be compared to that of an author and his publisher, but for the fact that Cooke himself had a share in the actual work of invention.
In 1840 Wheatstone had patented an alphabetical telegraph, or, 'Wheatstone A B C instrument,' which moved with a step-by-step motion, and showed the letters of the message upon a dial. The same principle was utilised in his type-printing telegraph, patented in 1841. This was the first apparatus which printed a telegram in type. It was worked by two circuits, and as the type revolved a hammer, actuated by the current, pressed the required letter on the paper. In 1840 Wheatstone also brought out his magneto-electrical machine for generating continuous currents, and his chronoscope, for measuring minute intervals of time, which was used in determining the speed of a bullet or the passage of a star. In this apparatus an electric current actuated an electro-magnet, which noted the instant of an occurrence by means of a pencil on a moving paper. It is said to have been capable of distinguishing 1/7300 part of a second, and the time a body took to fall from a height of one inch.
The same year he was awarded the Royal Medal of the Royal Society for his explanation of binocular vision, a research which led him to construct the stereoscope. He showed that our impression of solidity is gained by the combination in the mind of two separate pictures of an object taken by both of our eyes from different points of view. Thus, in the stereoscope, an arrangement of lenses and mirrors, two photographs of the same object taken from different points are so combined as to make the object stand out with a solid aspect. Sir David Brewster improved the stereoscope by dispensing with the mirrors, and bringing it into its existing form.
The 'pseudoscope' (Wheatstone was partial to exotic forms of speech) was introduced by its professor in 1850, and is in some sort the reverse of the stereoscope, since it causes a solid object to seem hollow, and a nearer one to be farther off; thus, a bust appears to be a mask, and a tree growing outside of a window looks as if it were growing inside the room.
On November 26, 1840, he exhibited his electro-magnetic clock in the library of the Royal Society, and propounded a plan for distributing the correct time from a standard clock to a number of local timepieces. The circuits of these were to be electrified by a key or contact-maker actuated by the arbour of the standard, and their hands corrected by electro-magnetism. The following January Alexander Bain took out a patent for an electro-magnetic clock, and he subsequently charged Wheatstone with appropriating his ideas. It appears that Bain worked as a mechanist to Wheatstone from August to December, 1840, and he asserted that he had communicated the idea of an electric clock to Wheatstone during that period; but Wheatstone maintained that he had experimented in that direction during May. Bain further accused Wheatstone of stealing his idea of the electro-magnetic printing telegraph; but Wheatstone showed that the instrument was only a modification of his own electro-magnetic telegraph.
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