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 a.s.sociation 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 Ampere, 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 pa.s.s 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 pa.s.sed 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 Inst.i.tute and the Legislative a.s.sembly. 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 s.p.a.ce 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 circ.u.mstances, 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 L80 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 L150.

In his latter years, while he resided in Glasgow, his health failed, and he was struck with paralysis in the legs. The ma.s.sive forehead once pregnant with the fire of genius, grew dull and slow of thought, while the st.u.r.dy 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 Lubeck 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. .h.i.therto 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 r.e.t.a.r.dation 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 acc.u.mulating 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. Soren 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 t.i.tle 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 a.s.sistant 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 r.e.t.a.r.dation 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 Inst.i.tution--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 t.i.tle 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-known ELECTRICAL TABLES AND FORMULAE, a work which was for a long time the electrician's VADE-MEc.u.m. 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 Inst.i.tution 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 Inst.i.tution of Electrical Engineers.