Heroes of the Telegraph/Appendix

From Wikisource
Jump to navigation Jump to search
3814309Heroes of the Telegraph — Appendix1891John Munro


APPENDIX.


I

CHARLES FERDINAND GAUSS.

Charles Ferdinand Gauss was born at Braunschweig on April 30, 1777. His father, George Dietrich, was a mason, who employed himself otherwise in the hard winter months, and finally became cashier to a Todtencasse, or burial fund. His mother Dorothy was the daughter of Christian Benze of the village of Velpke, near Braunschweig, and a woman of talent, industry, and wit, which her son appears to have inherited. The father died in 1808 after his son had become distinguished. The mother lived to the age of ninety-seven, but became totally blind. She preserved her low Saxon dialect, her blue linen dress and simple country manners, to the last, while living beside her son at the Observatory of Göttingen. Frederic, her younger brother, was a damask weaver, but a man with a natural turn for mathematics and mechanics.

When Gauss was a boy, his parents lived in a small house in the Wendengrahen, on a canal which joined the Ocker, a stream flowing through Braunschweig. The canal is now covered, and is the site of the Wilhelmstrasse, but a tablet marks the house. When a child, Gauss used to play on the bank of the canal, and falling in one day he was nearly drowned. He learned to read by asking the letters from his friends, and also by studying an old calendar which hung on a wall of his father's house, and when four years old he knew all the numbers on it, in spite of a shortness of sight which afflicted him to the end. On Saturday nights his father paid his workmen their wages, and once the boy, who had been listening to his calculations, jumped up and told him that he was wrong. Revision showed that his son was right.

At the age of seven, Gauss went to the Catherine Parish School at Braunschweig, and remained at it for several years. The master's name was Büttner, and from a raised seat in the middle of the room, he kept order by means of a whip suspended at his side. A bigger boy, Bartels by name, used to cut quill pens, and assist the smaller boys in their lessons. He became a friend of Gauss, and would procure mathematical books, which they read together. Bartels subsequently rose to be a professor in the University of Dorpat, where he died. At the parish school the boys of fourteen to fifteen years were being examined in arithmetic one day, when Gauss stepped forward and, to the astonishment of Büttner, requested to be examined at the same time. Büttner, thinking to punish him for his audacity, put a 'poser' to him, and awaited the result. Gauss solved the problem on his slate, and laid it face downward on the table, crying 'Here it is,' according to the custom. At the end of an hour, during which the master paced up and down with an air of dignity, the slates were turned over, and the answer of Gauss was found to be correct while many of the rest were erroneous. Büttner praised him, and ordered a special book on arithmetic for him all the way from Hamburg.

From the parish school Gauss went to the Catherine Gymnasium, although his father doubted whether he could afford the money. Bartels had gone there before him, and they read the higher mathematics. Gauss also devoted much of his time to acquiring the ancient and modern languages. From there he passed to the Carolinean College in the spring of 1792. Shortly before this the Duke Charles William Ferdinand of Braunschweig among others had noticed his talents, and promised to further his career.

In 1793 he published his first papers; and in the autumn of 1795 he entered the University of Gottingen. At this time he was hesitating between the pursuit of philology or mathematics; but his studies became more and more of the latter order. He discovered the division of the circle, a problem published in his Disquisitiones Arithmeticæ, and henceforth elected for mathematics. The method of least squares, was also discovered during his first term. On arriving home the duke received him in the friendliest manner, and he was promoted to Helmstedt, where with the assistance of his patron he published his Disquisitiones.

On January 1, 1801, Piazzi, the astronomer of Palermo, discovered a small planet, which he named Ceres Ferdinandia, and communicated the news by post to Bode of Berlin, and Oriani of Milan. The letter was seventy-two days in going, and the planet by that time was lost in the glory of the sun, By a method of his own, published in his Theoria Motus Corporum Cœlestium, Gauss calculated the orbit of this planet, and showed that it moved between Mars and Jupiter. The planet, after eluding the search of several astronomers, was ultimately found again by Zach on December 7, 1801, and on January 1, 1802. The ellipse of Gauss was found to coincide with its orbit.

This feat drew the attention of the Hanoverian Government, and of Dr. Olbers, the astronomer, to the young mathematician. But some time elapsed before he was fitted with a suitable appointment. The battle of Austerlitz had brought the country into danger, and the Duke of Braunschweig was entrusted with a mission from Berlin to the Court of St. Petersburg. The fame of Gauss had travelled there, but the duke resisted all attempts to bring or entice him to the university of that place. On his return home, however, he raised the salary of Gauss.

At the beginning of October 1806, the armies of Napoleon were moving towards the Saale, and ere the middle of the month the battles of Auerstadt and Jena were fought and lost. Duke Charles Ferdinand was mortally wounded, and taken back to Braunschweig. A deputation waited on the offended Emperor at Halle, and begged him to allow the aged duke to die in his own house. They were brutally denied by the Emperor, and returned to Braunschweig to try and save the unhappy duke from imprisonment. One evening in the late autumn, Gauss, who lived in the Steinweg (or Causeway), saw an invalid carriage drive slowly out of the castle garden towards the Wendenthor. It contained the wounded duke on his way to Altona, where he died on November 10, 1806, in a small house at Ottensen, 'You will take care,' wrote Zach to Gauss, in 1803, 'that his great name shall also be written on the firmament.'

For a year and a half after the death of the duke Gauss continued in Braunschweig, but his small allowance, and the absence of scientific company made a change desirable. Through Olbers and Heeren he received a call to the directorate of Göttingen University in 1807, and at once accepted it. He took a house near the chemical laboratory, to which he brought his wife and family. The building of the observatory, delayed for want of funds, was finished in 1816, and a year or two later it was fully equipped with instruments.

In 1819, Gauss measured a degree of latitude between Göttingen and Altona. In geodesy he invented the heliotrope, by which the sunlight reflected from a mirror is used as a "sight" for the theodolite at a great distance. Through Professor William Weber he was introduced to the science of electro-magnetism, and they devised an experimental telegraph, chiefly for sending time signals, between the Observatory and the Physical Cabinet of the University. The mirror receiving instrument employed was the heavy prototype of the delicate reflecting galvanometer of Sir William Thomson. In 1834 messages were transmitted through the line in presence of H.R.H. the Duke of Cambridge; but it was hardly fitted for general use. In 1883 (?) he published an absolute system of magnetic measurements.

On July 16, 1849, the jubilee of Gauss was celebrated at the University; the famous Jacobi, Miller of Cambridge, and others, taking part in it. After this he completed several works already begun, read a great deal of German and foreign literature, and visited the Museum daily between eleven and one o'clock.

In the winters of 1854-5 Gauss complained of his declining health, and on the morning of February 23, 1855, about five minutes past one o'clock, he breathed his last. He was laid on a bed of laurels, and buried by his friends. A granite pillar marks his resting-place at Göttingen.


II.

WILLIAM EDWARD WEBER.

William Edward Weber was born on October 24, 1804, at Wittenberg, where his father, Michael Weber, was professor of theology. William was the second of three brothers, all of whom were distinguished by an aptitude for the study of science. After the dissolution of the University of Wittenberg his father was transferred to Halle in 1815. William had received his first lessons from his father, but was now sent to the Orphan Asylum and Grammar School at Halle. After that he entered the University, and devoted himself to natural philosophy. He distinguished himself so much in his classes, and by original work, that after taking his degree of Doctor and becoming a Privat-Docent he was appointed Professor Extraordinary of natural philosophy at Halle.

In 1831, on the recommendation of Gauss, he was called to Göttingen as professor of physics, although but twenty-seven years of age. His lectures were interesting, instructive, and suggestive. Weber thought that, in order to thoroughly understand physics and apply it to daily life, mere lectures, though illustrated by experiments, were insufficient, and he encouraged his students to experiment themselves, free of charge, in the college laboratory. As a student of twenty years he, with his brother, Ernest Henry Weber, Professor of Anatomy at Leipsic, had written a book on the 'Wave Theory and Fluidity,' which brought its authors a considerable reputation. Acoustics was a favourite science of his, and he published numerous papers upon it in Poggendorff's Annalen, Schweigger's Jahrbücher für Chemie und Physik, and the musical journal Cæcilia. The 'mechanism of walking in mankind' was another study, undertaken in conjunction with his younger brother, Edward Weber. These important investigations were published between the years 1825 and 1838.

Displaced by the Hanoverian Government for his liberal opinions in politics Weber travelled for a time, visiting England, among other countries, and became professor of physics in Leipsic from 1843 to 1849, when he was reinstalled at Göttingen. One of his most important works was the Atlas des Erdmagnetismus, a series of magnetic maps, and it was chiefly through his efforts that magnetic observatories were instituted. He studied magnetism with Gauss, and in 1864 published his 'Electrodynamic Proportional Measures' containing a system of absolute measurements for electric currents, which forms the basis of those in use. Weber died at Göttingen on June 23, 1891.


III.

SIR WILLIAM FOTHERGILL COOKE.

William Fothergill Cooke was born near Ealing on May 4, 1806, and was a son of Dr. William Cooke, a doctor of medicine, and professor of anatomy at the University of Durham. The boy was educated at a school in Durham, and at the University of Edinburgh. In 1826 he joined the East India Army, and held several staff appointments. While in the Madras Native Infantry, he returned home on furlough, owing to ill-health, and afterwards relinquished this connection. In 1833-4 he studied anatomy and physiology in Paris, acquiring great skill at modelling dissections in coloured wax.

In the summer of 1835, while touring in Switzerland with his parents, he visited Heidelberg, and was induced by Professor Tiedeman, director of the Anatomical Institute, to return there and continue his wax modelling. He lodged at 97, Stöckstrasse, in the house of a brewer, and modelled in a room nearly opposite. Some of his models have been preserved in the Anatomical Museum at Heidelberg. In March 1836, hearing accidentally from Mr. J. W. R. Hoppner, a son of Lord Byron's friend, that the Professor of Natural Philosophy in the University, Geheime Hofrath Möncke had a model of Baron Schilling's telegraph, Cooke went to see it on March 6, in the Professor's lecture room, an upper storey of an old convent of Dominicans, where he also lived. Struck by what he witnessed, he abandoned his medical studies, and resolved to apply all his energies to the introduction of the telegraph. Within three weeks he had made, partly at Heidelberg, and partly at Frankfort, his first galvanometer, or needle telegraph. It consisted of three magnetic needles surrounded by multiplying coils, and actuated by three separate circuits of six wires. The movements of the needles under the action of the currents produced twenty-six different signals corresponding to the letters of the alphabet.

'Whilst completing the model of my original plan,' he wrote to his mother on April 5, 'others on entirely fresh systems suggested themselves, and I have at length succeeded in combining the utile of each, but the mechanism requires a more delicate hand than mine to execute, or rather instruments which I do not possess. These I can readily have made for me in London, and by the aid of a lathe I shall be able to adapt the several parts, which I shall have made by different mechanicians for secrecy's sake. Should I succeed, it may be the means of putting some hundreds of pounds in my pocket. As it is a subject on which I was profoundly ignorant, until my attention was casually attracted to it the other day, I do not know what others may have done in the same way; this can best be learned in London.'

The 'fresh systems' referred to was his 'mechanical' telegraph, consisting of two letter dials, working synchronously, and on which particular letters of the message were indicated by means of an electro-magnet and detent. Before the end of March he invented the clock-work alarm, in which an electro-magnet attracted an armature of soft iron, and thus withdrew a detent, allowing the works to strike the alarm. This idea was suggested to him on March 17, 1836, while reading Mrs. Mary Somerville's 'Connexion of the Physical Sciences,' in travelling from Heidelberg to Frankfort.

Cooke arrived in London on April 22, and wrote a pamphlet setting forth his plans for the establishment of an electric telegraph; but it was never published. According to his own account he also gave considerable attention to the escapement principle, or step by step movement, afterwards perfected by Wheatstone. While busy in preparing his apparatus for exhibition, part of which was made by a clock-maker in Clerkenwell, he consulted Faraday about the construction of electro-magnets, The philosopher saw his apparatus and expressed his opinion that the 'principle was perfectly correct,' and that the 'instrument appears perfectly adapted to its intended uses.' Nevertheless he was not very sanguine of making it a commercial success. 'The electro-magnetic telegraph shall not ruin me,' he wrote to his mother, 'but will hardly make my fortune.' He was desirous of taking a partner in the work, and went to Liverpool in order to meet some gentleman likely to forward his views, and endeavoured to get his instrument adopted on the incline of the tunnel at Liverpool; but it gave sixty signals, and was deemed too complicated by the directors. Soon after his return to London, by the end of April, he had two simpler instruments in working order. All these preparations had already cost him nearly four hundred pounds.

On February 27, Cooke, being dissatisfied with an experiment on a mile of wire, consulted Faraday and Dr. Roget as to the action of a current on an electro-magnet in circuit with a long wire. Dr. Roget sent him to Wheatstone, where to his dismay he learned that Wheatstone had been employed for months on the construction of a telegraph for practical purposes. The end of their conferences was that a partnership in the undertaking was proposed by Cooke, and ultimately accepted by Wheatstone. The latter had given Cooke fresh hopes of success when he was worn and discouraged. 'In truth,' he wrote in a letter, after his first interview with the Professor, 'I had given the telegraph up since Thursday evening, and only sought proofs of my being right to do so ere announcing it to you. This day's enquiries partly revives my hopes, but I am far from sanguine. The scientific men know little or nothing absolute on the subject: Wheatstone is the only man near the mark.'

It would appear that the current, reduced in strength by its passage through a long wire, had failed to excite his electro-magnet, and he was ignorant of the reason. Wheatstone by his knowledge of Ohm's law and the electro-magnet was probably able to enlighten him. It is clear that Cooke had made considerable progress with his inventions before he met Wheatstone; he possessed a needle telegraph like Wheatstone, an alarm, and a chronometric dial telegraph, which at all events are a proof that he himself was an inventor, and that he doubtless bore a part in the production of the Cooke and Wheatstone apparatus. Contrary to a statement of Wheatstone, it appears from a letter of Cooke dated March 4, 1837, that Wheatstone 'handsomely acknowledged the advantage' of Cooke's apparatus had it worked;' his (Wheatstone's) are ingenious, but not practicable.' But these conflicting accounts are reconciled by the fact that Cooke's electro-magnetic telegraph would not work, and Wheatstone told him so, because he knew the magnet was not strong enough when the current had to traverse a long circuit.

Wheatstone subsequently investigated the conditions necessary to obtain electro-magnetic effects at a long distance. Had he studied the paper of Professor Henry in Silliman's Journal for January 1831, he would have learned that in a long circuit the electro-magnet had to be wound with a long and fine wire in order to be effective.

As the Cooke and Wheatstone apparatus became perfected, Cooke was busy with schemes for its introduction. Their joint patent is dated June 12, 1837, and before the end of the month Cooke was introduced to Mr. Robert Stephenson, and by his address and energy got leave to try the invention from Euston to Camden Town along the line of the London and Birmingham Railway. Cooke suspended some thirteen miles of copper, in a shed at the Euston terminus, and exhibited his needle and his chronometric telegraph in action to the directors one morning. But the official trial took place as we have already described in the life of Wheatstone.

The telegraph was soon adopted on the Great Western Railway, and also on the Blackwall Railway in 1841. Three years later it was tried on a Government line from London to Portsmouth. In 1845, the Electric Telegraph Company, the pioneer association of its kind, was started, and Mr. Cooke became a director. Wheatstone and he obtained a considerable sum for the use of their apparatus. In 1866, Her Majesty conferred the honour of knighthood on the co-inventors; and in 1871, Cooke was granted a Civil List pension of L100 a year. His latter years were spent in seclusion, and he died at Farnham on June 25th, 1879. Outside of telegraphic circles his name had become well-nigh forgotten.


IV.

ALEXANDER BAIN.

Alexander Bain was born of humble parents in the little town of Thurso, at the extreme north of Scotland, in the year 1811. At the age of twelve he went to hear a penny lecture on science which, according to his own account, set him thinking and influenced his whole future. Learning the art of clockmaking, he went to Edinburgh, and subsequently removed to London, where he obtained work in Clerkenwell, then famed for its clocks and watches. His first patent is dated January 11th, 1841, and is in the name of John Barwise, chronometer maker, and Alexander Bain, mechanist, Wigmore Street. It describes his electric clock in which there is an electro-magnetic pendulum, and the electric current is employed to keep it going instead of springs or weights. He improved on this idea in following patents, and also proposed to derive the motive electricity from an 'earth battery,' by burying plates of zinc and copper in the ground. Gauss and Steinheil had priority in this device which, owing to 'polarisation' of the plates and to drought, is not reliable. Long afterwards Mr. Jones of Chester succeeded in regulating timepieces from a standard astronomical clock by an improvement on the method of Bain. On December 21, 1841, Bain, in conjunction with Lieut. Thomas Wright, R.N., of Percival Street, Clerkenwell, patented means of applying electricity to control railway engines by turning off the steam, marking time, giving signals, and printing intelligence at different places. He also proposed to utilise 'natural bodies of water' for a return wire, but the earlier experimenters had done so, particularly Steinheil in 1838. The most important idea in the patent is, perhaps, his plan for inverting the needle telegraph of Ampère, Wheatstone and others, and instead of making the signals by the movements of a pivoted magnetic needle under the influence of an electrified coil, obtaining them by suspending a movable coil traversed by the current, between the poles of a fixed magnet, as in the later siphon recorder of Sir William Thomson. Bain also proposed to make the coil record the message by printing it in type; and he developed the idea in a subsequent patent.

Next year, on December 31st, 1844, he projected a mode of measuring the speed of ships by vanes revolving in the water and indicating their speed on deck by means of the current. In the same specification he described a way of sounding the sea by an electric circuit of wires, and of giving an alarm when the temperature of a ship's hold reached a certain degree. The last device is the well-known fire-alarm in which the mercury of a thermometer completes an electric circuit, when it rises to a particular point of the tube, and thus actuates an electric bell or other alarm.

On December 12, 1846, Bain, who was staying in Edinburgh at that time, patented his greatest invention, the chemical telegraph, which bears his name. He recognised that the Morse and other telegraph instruments in use were comparatively slow in speed, owing to the mechanical inertia of the parts; and he saw that if the signal currents were made to pass through a band of travelling paper soaked in a solution which would decompose under their action, and leave a legible mark, a very high speed could be obtained. The chemical he employed to saturate the paper was a solution of nitrate of ammonia and prussiate of potash, which left a blue stain on being decomposed by the current from an iron contact or stylus. The signals were the short and long, or 'dots' and 'dashes' of the Morse code. The speed of marking was so great that hand signalling could not keep up with it, and Bain devised a plan of automatic signalling by means of a running band of paper on which the signals of the message were represented by holes punched through it. Obviously if this tape were passed between the contact of a signalling key the current would merely flow when the perforations allowed the contacts of the key to touch. This principle was afterwards applied by Wheatstone in the construction of his automatic sender.

The chemical telegraph was tried between Paris and Lille before a committee of the Institute and the Legislative Assembly. The speed of signalling attained was 282 words in fifty-two seconds, a marvellous advance on the Morse electro-magnetic instrument, which only gave about forty words a minute. In the hands of Edison the neglected method of Bain was seen by Sir William Thomson in the Centennial Exhibition, Philadelphia, recording at the rate of 1057 words in fifty-seven seconds. In England the telegraph of Bain was used on the lines of the old Electric Telegraph Company to a limited extent, and in America about the year 1850 it was taken up by the energetic Mr. Henry O'Reilly, and widely introduced. But it incurred the hostility of Morse, who obtained an injunction against it on the slender ground that the running paper and alphabet used were covered by his patent. By 1859, as Mr. Shaffner tells us, there was only one line in America on which the Bain system was in use, namely, that from Boston to Montreal. Since those days of rivalry the apparatus has never become general, and it is not easy to understand why, considering its very high speed, the chemical telegraph has not become a greater favourite.

In 1847 Bain devised an automatic method of playing on wind instruments by moving a band of perforated paper which controlled the supply of air to the pipes; and likewise proposed to play a number of keyed instruments at a distance by means of the electric current. Both of these plans are still in operation.

These and other inventions in the space of six years are a striking testimony to the fertility of Bain's imagination at this period. But after this extraordinary outburst he seems to have relapsed into sloth and the dissipation of his powers. We have been told, and indeed it is plain that he received a considerable sum for one or other of his inventions, probably the chemical telegraph. But while he could rise from the ranks, and brave adversity by dint of ingenuity and labour, it would seem that his sanguine temperament was ill-fitted for prosperity. He went to America, and what with litigation, unfortunate investment, and perhaps extravagance, the fortune he had made was rapidly diminished.

Whether his inventive genius was exhausted, or he became disheartened, it would be difficult to say, but he never flourished again. The rise in his condition may be inferred from the preamble to his patent for electric telegraphs and clocks, dated May 29, 1852, wherein he describes himself as 'Gentleman,' and living at Beevor Lodge, Hammersmith. After an ephemeral appearance in this character he sank once more into poverty, if not even wretchedness. Moved by his unhappy circumstances, Sir William Thomson, the late Sir William Siemens, Mr. Latimer Clark and others, obtained from Mr. Gladstone, in the early part of 1873, a pension for him under the Civil List of £80 a year; but the beneficiary lived in such obscurity that it was a considerable time before his lodging could be discovered, and his better fortune take effect. The Royal Society had previously made him a gift of £150.

In his latter years, while he resided in Glasgow, his health failed, and he was struck with paralysis in the legs. The massive forehead once pregnant with the fire of genius, grew dull and slow of thought, while the sturdy frame of iron hardihood became a tottering wreck. He was removed to the Home for Incurables at Broomhill, Kirkintilloch, where he died on January 2, 1877, and was interred in the Old Aisle Cemetery. He was a widower, and had two children, but they were said to be abroad at the time, the son in America and the daughter on the Continent.

Several of Bain's earlier patents are taken out in two names, but this was perhaps owing to his poverty compelling him to take a partner. If these and other inventions were substantially his own, and we have no reason to suppose that he received more help from others than is usual with inventors, we must allow that Bain was a mechanical genius of the first order—a born inventor. Considering the early date of his achievements, and his lack of education or pecuniary resource, we cannot but wonder at the strength, fecundity, and prescience of his creative faculty. It has been said that he came before his time; but had he been more fortunate in other respects, there is little doubt that he would have worked out and introduced all or nearly all his inventions, and probably some others. His misfortunes and sorrows are so typical of the 'disappointed inventor' that we would fain learn more about his life; but beyond a few facts in a little pamphlet (published by himself, we believe), there is little to be gathered; a veil of silence has fallen alike upon his triumphs, his errors and his miseries.


V.

Dr. WERNER SIEMENS.

The leading electrician of Germany is Dr. Ernst Werner Siemens, eldest brother of the same distinguished family of which our own Sir William Siemens was a member. Ernst, like his brother William, was born at Lenthe, near Hanover, on December 13, 1816. He was educated at the College of Lübeck in Maine, and entered the Prussian Artillery service as a volunteer. He pursued his scientific studies at the Artillery and Engineers' School in Berlin, and in 1838 obtained an officer's commission.

Physics and chemistry were his favourite studies; and his original researches in electro-gilding resulted in a Prussian patent in 1841. The following year he, in conjunction with his brother William, took out another patent for a differential regulator. In 1844 he was appointed to a post in the artillery workshops in Berlin, where he learned telegraphy, and in 1845 patented a dial and printing telegraph, which is still in use in Germany.

In 1846, he was made a member of a commission organised in Berlin to introduce electric telegraphs in place of the optical ones hitherto employed in Prussia, and he succeeded in getting the commission to adopt underground telegraph lines. For the insulation of the wires he recommended gutta-percha, which was then becoming known as an insulator. In the following year he constructed a machine for covering copper wire with the melted gum by means of pressure; and this machine is substantially the same as that now used for the purpose in cable factories.

In 1848, when the war broke out with Denmark, he was sent to Kiel where, together with his brother-in-law, Professor C. Himly, he laid the first submarine mines, fired by electricity and thus protected the town of Kiel from the advance of the enemies' fleet.

Of late years the German Government has laid a great network of underground lines between the various towns and fortresses of the empire; preferring them to overhead lines as being less liable to interruption from mischief, accident, hostile soldiers, or stress of weather. The first of such lines was, however, laid as long ago as 1848, by Werner Siemens, who, in the autumn of that year, deposited a subterranean cable between Berlin and Frankfort-on-the-Main. Next year a second cable was laid from the Capital to Cologne, Aix-la-Chapelle, and Verviers.

In 1847 the subject of our memoir had, along with Mr. Halske, founded a telegraph factory, and he now left the army to give himself up to scientific work and the development of his business. This factory prospered well, and is still the chief continental works of the kind. The new departure made by Werner Siemens was fortunate for electrical science; and from then till now a number of remarkable inventions have proceeded from his laboratory.

The following are the more notable advances made:—In October 1845, a machine for the measurement of small intervals of time, and the speed of electricity by means of electric sparks, and its application in 1875 for measuring the speed of the electric current in overland lines.

In January 1850, a paper on telegraph lines and apparatus, in which the theory of the electro-static charge in insulated wires, as well as methods and formula: for the localising of faults in underground wires were first established. In 1851, the firm erected the first automatic fire telegraphs in Berlin, and in the same year, Werner Siemens wrote a treatise on the experience gained with the underground lines of the Prussian telegraph system. The difficulty of communicating through long underground lines led him to the invention of automatic translation, which was afterwards improved upon by Steinheil, and, in 1852, he furnished the Warsaw-Petersburg line with automatic fast-speed writers. The messages were punched in a paper band by means of the well-known Siemens' lever punching apparatus, and then automatically transmitted in a clockwork instrument.

In 1854 the discovery (contemporaneous with that of Frischen) of simultaneous transmission of messages in opposite directions, and multiplex transmission of messages by means of electro-magnetic apparatus. The 'duplex' system which is now employed both on land lines and submarine cables had been suggested however, before this by Dr. Zetsche, Gintl, and others.

In 1856 he invented the Siemens' magneto-electric dial instrument giving alternate currents. From this apparatus originated the well-known Siemens' armature, and from the receiver was developed the Siemens' polarised relay, with which the working of submarine and other lines could be effected with alternate currents; and in the same year, during the laying of the Cagliari to Bona cable, he constructed and first applied the dynamometer, which has become of such importance in the operations of cable laying.

In 1857, he investigated the electro-static induction and retardation of currents in insulated wires, a phenomenon which he had observed in 1850, and communicated an account of it to the French Academy of Sciences.

'In these researches he developed mathematically Faraday's theory of molecular induction, and thereby paved the way in great measure for its general acceptance.' His ozone apparatus, his telegraph instrument working with alternate currents, and his instrument for translating on and automatically discharging submarine cables also belong to the year 1857. The latter instruments were applied to the Sardinia, Malta, and Corfu cable.

In 1859, he constructed an electric log; he discovered that a dielectric is heated by induction; he introduced the well known Siemens' mercury unit, and many improvements in the manufacture of resistance coils. He also investigated the law of change of resistance in wires by heating; and published several formulae and methods for testing resistances and determining 'faults' by measuring resistances. These methods were adopted by the electricians of the Government service in Prussia, and by Messrs. Siemens Brothers in London, during the manufacture of the Malta to Alexandria cable, which, was, we believe, the first long cable subjected to a system of continuous tests.

'In 1861, he showed that the electrical resistance of molten alloys is equal to the sum of the resistances of the separate metals, and that latent heat increases the specific resistance of metals in a greater degree than free heat.' In 1864 he made researches on the heating of the sides of a Leyden jar by the electrical discharge. In 1866 he published the general theory of dynamo-electric machines, and the principle of accumulating the magnetic effect, a principle which, however, had been contemporaneously discovered by Mr. S. A. Varley, and described in a patent some years before by Mr. Sören Hjorth, a Danish inventor. Hjorth's patent is to be found in the British Patent Office Library, and until lately it was thought that he was the first and true inventor of the 'dynamo' proper, but we understand there is a prior inventor still, though we have not seen the evidence in support of the statement.

The reversibility of the dynamo was enunciated by Werner Siemens in 1867; but it was not experimentally demonstrated on any practical scale until 1870, when M. Hippolite Fontaine succeeded in pumping water at the Vienna international exhibition by the aid of two dynamos connected in circuit; one, the generator, deriving motion from a hydraulic engine, and in turn setting in motion the receiving dynamo which worked the pump. Professor Clerk Maxwell thought this discovery the greatest of the century; and the remark has been repeated more than once. But it is a remark which derives its chief importance from the man who made it, and its credentials from the paradoxical surprise it causes. The discovery in question is certainly fraught with very great consequences to the mechanical world; but in itself it is no discovery of importance, and naturally follows from Faraday's far greater and more original discovery of magneto-electric generation.

In 1874, Dr. Siemens published a treatise on the laying and testing of submarine cables. In 1875, 1876 and 1877, he investigated the action of light on crystalline selenium, and in 1878 he studied the action of the telephone.

The recent work of Dr. Siemens has been to improve the pneumatic railway, railway signalling, electric lamps, dynamos, electro-plating and electric railways. The electric railway at Berlin in 1880, and Paris in 1881, was the beginning of electric locomotion, a subject of great importance and destined in all probability, to very wide extension in the immediate future. Dr. Siemens has received many honours from learned societies at home and abroad; and a title equivalent to knighthood from the German Government.


VI.

LATIMER CLARK.

Mr. Clark was born at Great Marlow in 1822, and probably acquired his scientific bent while engaged at a manufacturing chemist's business in Dublin. On the outbreak of the railway mania in 1845 he took to surveying, and through his brother, Mr. Edwin Clark, became assistant engineer to the late Robert Stephenson on the Britannia Bridge. While thus employed, he made the acquaintance of Mr. Ricardo, founder of the Electric Telegraph Company, and joined that Company as an engineer in 1850. He rose to be chief engineer in 1854, and held the post till 1861, when he entered into a partnership with Mr. Charles T. Bright. Prior to this, he had made several original researches; in 1853, he found that the retardation of current on insulated wires was independent of the strength of current, and his experiments formed the subject of a Friday evening lecture by Faraday at the Royal Institution—a sufficient mark of their importance.

In 1854 he introduced the pneumatic dispatch into London, and, in 1856, he patented his well-known double-cup insulator. In 1858, he and Mr. Bright produced the material known as 'Clark's Compound,' which is so valuable for protecting submarine cables from rusting in the sea-water. In 1859, Mr. Clark was appointed engineer to the Atlantic Telegraph Company which tried to lay an Anglo-American cable in 1865. in partnership with Sir C. T. Bright, who had taken part in the first Atlantic cable expedition, Mr. Clark laid a cable for the Indian Government in the Red Sea, in order to establish a telegraph to India. In 1886, the partnership ceased; but, in 1869, Mr Clark went out to the Persian Gulf to lay a second cable there. Here he was nearly lost in the shipwreck of the Carnatic on the Island of Shadwan in the Red Sea.

Subsequently Mr. Clark became the head of a firm of consulting electricians, well known under the title of Clark, Forde and Company, and latterly including the late Mr. C. Hockin and Mr. Herbert Taylor.

The Mediterranean cable to India, the East Indian Archipelago cable to Australia, the Brazilian Atlantic cables were all laid under the supervision of this firm. Mr. Clark is now in partnership with Mr. Stanfield, and is the joint-inventor of Clark and Stanfield's circular floating dock. He is also head of the well-known firm of electrical manufacturers, Messrs. Latimer Clark, Muirhead and Co., of Regency Street, Westminster.

The foregoing sketch is but an imperfect outline of a very successful life. `But enough has been given to show that we have here an engineer of various and even brilliant gifts. Mr. Clark has applied himself in divers directions, and never applied himself in vain. There is always some practical result to show which will be useful to others. In technical literature he published a description of the Conway and Britannia Tubular Bridges as long ago as 1849. There is a valuable communication of his in the Board of Trade Blue Rook on Submarine Cables. In 1868, he issued a useful work on Electrical Measurements, and in 1871 joined with Mr. Robert Sabine in producing the well-knownElectrical Tables and Formulæ, a work which was for a long time the electrician's vade-mecum. In 1873, he communicated a lengthy paper on the New Standard of Electromotive Power now known as Clark's Standard Cell; and quite recently he published a treatise on the Use of the Transit Instrument.

Mr. Clark is a Fellow of the Royal Society of London, as well as a member of the Institution of Civil Engineers, the Royal Astronomical Society, the Physical Society, etc., and was elected fourth President of the Society of Telegraph Engineers and of Electricians, now the Institution of Electrical Engineers.

He is a great lover of books and gardening—two antithetical hobbies—which are charming in themselves, and healthily counteractive. The rich and splendid library of electrical works which he is forming, has been munificently presented to the Institution of Electrical Engineers.


VII.

COUNT DU MONCEL.

Théodose-Achille-Louis, Comte du Moncel, was born at Paris on March 6, 1821. His father was a peer of France, one of the old nobility, and a General of Engineers. He possessed a model farm near Cherbourg, and had set his heart on training his son to carry on this pet project; but young Du Moncel, under the combined influence of a desire for travel, a love of archaeology, and a rare talent for drawing, went off to Greece, and filled his portfolio with views of the Parthenon and many other pictures of that classic region. His father avenged himself by declining to send him any money; but the artist sold his sketches and relied solely on his pencil. On returning to Paris he supported himself by his art, but at the same time gratified his taste for science in a discursive manner. A beautiful and accomplished lady of the Court, Mademoiselle Camille Clementine Adélaïde Bachasson de Montalivet, belonging to a noble and distinguished family, had plighted her troth with him, and, as we have been told, descended one day from her carriage, and wedded the man of her heart, in the humble room of a flat not far from the Grand Opera House. They were a devoted pair, and Madame du Moncel played the double part of a faithful help-meet, and inspiring genius. Heart and soul she encouraged her husband to distinguish himself by his talents and energy, and even assisted him in his labours.

About 1852 he began to occupy himself almost exclusively with electrical science. His most conspicuous discovery is that pressure diminishes the resistance of contact between two conductors, a fact which Clerac in 1866 utilised in the construction of a variable resistance from carbon, such as plumbage, by compressing it with an adjustable screw. It is also the foundation of the carbon transmitter of Edison, and the more delicate microphone of Professor Hughes. But Du Moncel is best known as an author and journalist. His 'Exposé des applications de l'électricité' published in 1856 et seq., and his 'Traité pratique de Télégraphie,' not to mention his later books on recent marvels, such as the telephone, microphone, phonograph, and electric light, are standard works of reference. In the compilation of these his admirable wife assisted him as a literary amanuensis, for she had acquired a considerable knowledge of electricity.

In 1866 he was created an officer of the Legion of Honour, and he became a member of numerous learned societies. For some time he was an adviser of the French telegraph administration, but resigned the post in 1873. The following year he was elected a Member of the Academy of Sciences, Paris. In 1879, he became editor of a new electrical journal established at Paris under the title of 'La Lumière Électrique,' and held the position until his death, which happened at Paris after a few days' illness on February 16, 1884. His devoted wife was recovering from a long illness which had caused her affectionate husband much anxiety, and probably affected his health. She did not long survive him, but died on February 4, 1887, at Mentone in her fifty-fifth year. Count du Moncel was an indefatigable worker, who, instead of abandoning himself to idleness and pleasure like many of his order, believed it his duty to be active and useful in his own day, as his ancestors had been in the past.


VIII.

ELISHA GRAY.

This distinguished American electrician was born at Barnesville in Belmont county, Ohio, on August 2, 1835. His family were Quakers, and in early life he was apprenticed to a carpenter, but showed a taste for chemistry, and at the age of twenty-one he went to Oberlin College, where he studied for five years. At the age of thirty he turned his attention to electricity, and invented a relay which adapted itself to the varying insulation of the telegraph line. He was then led to devise several forms of automatic repeaters, but they are not much employed. In 1870-2, he brought out a needle annunciator for hotels, and another for elevators, which had a large sale. His 'Private Telegraph Line Printer' was also a success. From 1873-5 he was engaged in perfecting his 'Electro-harmonic telegraph.' His speaking telegraph was likewise the outcome of these researches. The 'Telautograph,' or telegraph which writes the messages as a fac-simile of the sender's penmanship by an ingenious application of intermittent currents, is the latest of his more important works. Mr. Gray is a member of the firm of Messrs. Gray and Barton, and electrician to the Western Electric Manufacturing Company of Chicago. His home is at Highland Park near that city.