Story Lives of Great Scientists - F. J. Rowbotham




Michael Faraday

Michael Faraday

MICHAEL FARADAY.


The new errand-boy at Mr. Riebau's, bookseller and stationer, of Blandford Street, Manchester Square, had just taken down the shutters of his master's shop one morning in the autumn of 1804. The shutters having been stowed away the boy was given a large parcel of newspapers to deliver, with injunctions to be careful to leave them at the right houses. In those days newspapers were often lent out, and after being delivered had to be called for again. It not unfrequently happened on Sunday mornings that the paper when called for was not ready, so that the boy had to go over the same ground twice. This was very irksome to the lad, his anxiety being to get home and tidy himself in order to accompany his parents to their place of worship. To save himself the double journey he would plead for the paper to be given to him, and wait patiently at the door until the late-risen customer had devoured his muffins and the news together.

It was a long and weary round; but after all, it was better than playing marbles in the street, or taking his baby sister for an airing round the Square. At any rate he was helping his parents (who were very poor) to keep himself and his little brothers and sisters, as his elder brother was doing. So thought young Michael Faraday; and he soon had good cause to feel glad at having found employment under a kind master such as Mr. Riebau proved to be.

At the time our story opens Michael's parents were living in rooms over a coach-house in Jacob's Well Mews, Charles Street, Manchester Square. Robert Faraday had very bad health, and found it a difficult matter to support his family by working as journeyman for a firm in the neighbourhood. During the distress of 1801, when the price of corn rose to over q a quarter, the Faradays, in common with numbers of poor families at that period, received parish relief, and Michael, who was then nine, received for his share one loaf a week, and had to make it last for that time. Hence there was a necessity for the boys becoming wage-earners at an early age, and Michael in his turn, on reaching his twelfth year, and having received some rudimentary, instruction at a common day-school, was sent on trial for one year to the shop of Mr. Riebau, the bookseller of Blandford Street.

It was a small beginning, but Michael soon found his interest awakened in connection with his master's stock-in-trade. Being surrounded by books and having to handle them constantly, he grew familiar with their titles first and afterwards was led to taste their contents. When his year's trial came to an end he was bound apprentice to the bookbinding trade, and the indenture of apprenticeship contained this testimony to his conduct: "In consideration of his faithful service no premium is given." He writes of these early days:—"Whilst an apprentice I loved to read the scientific books which were under my hand." Amongst others, Mrs. Marcet's Conversations in Chemistry  excited his interest and occupied his spare moments. Watts' On the Improvement of the Mind  made him think, and an article on Electricity in the Encyclopedia Britannica,  which he read as he bound the volume, first turned his attention seriously to science. He was called upon to bind other books of a scientific kind, such as Lyon's Experiments on Electricity  and Boyle's Notes about the Producibleness of Chymicall Principles;  and dipped into them as he bound them.

About this time, he tells us, "I made such simple experiments in chemistry as could be defrayed in their expense by a few pence per week, and also constructed an electrical machine, first with a glass phial, and afterwards with a real cylinder, as well as other electrical apparatus of a corresponding kind." He had thus made a real beginning in science, and these first steps led on to others. Riebau seems to have taken a friendly interest in his studies and to have encouraged him by allowing him to read the books he wanted.

One day early in the year 1810 Faraday's eye caught an announcement in a shop window to the effect that a course of lectures on Natural Philosophy would be given by Mr. Tatum at his house No. 53 Dorset Street, Fleet Street, at 8 o'clock; price of admission one shilling per lecture. His weekly pittance did not allow of his treating himself to this intellectual feast, but his elder brother Robert, the blacksmith, good-naturedly put the first shilling into his hand, and followed this up by other like gifts from time to time; so that Michael joyfully wended his way to Dorset Street upon some dozen occasions between February, 181 o, and September, 181 1. He took full notes of what he heard, afterwards writing out each lecture at length. To illustrate his notes, as he had no knowledge of drawing, he sought the help of an artist named Masquerier, a French refugee, who lodged at Riebau's, and who had acquired some fame by painting the portrait of Napoleon. Masquerier took a liking to Faraday, and not only gave him some lessons but lent him a book on perspective, by the aid of which Faraday was enabled to make correct diagrams.

Tatum's house was the resort of numerous students—young and enthusiastic, as Faraday himself was—and here he made the acquaintance of Magrath, Newton, Huxtable, Nicol, and Abbott. With several of these he soon got on terms of friendship, and Benjamin Abbott, a young Quaker of good education, and holding the position of confidential clerk in a City house, became his most intimate friend and correspondent. Huxtable, who was a medical student, lent him books on chemistry. The picture of Faraday at this time is that of an earnest student, striving to educate himself in the face of poverty, though by no means struggling against other adverse conditions such as have assailed many young men of worth and ability; for Faraday had in his favour good health, natural energy, an absence of responsibility outside his own requirements, and kindly disposed friends—circumstances, all of them of powerful effect in assisting his progress when weighed against mere shortness of money.

He possessed a natural capacity for making friends and of enlisting sympathy, and thus it came about that Mr. Dance, a member of the Royal Institution, and one of Riebau's customers, was so favourably impressed by what he had observed of Faraday's diligent pursuit of science, that he procured him admission to the last four lectures given by Sir Humphry Davy at the Royal Institution (February to April, 1812). This privilege Faraday made the best use of by taking full notes of each lecture at the time and writing them out fully and fairly afterwards, introducing his own sketches in illustration. The fire which had already been kindled now burnt fiercely within him, and his longing for a scientific occupation led him to write a letter to Sir Joseph Banks, then President of the Royal Society, begging to be employed in some capacity in science. Needless to say, "No answer" was the reply left with the porter. But more than this dash of cold water was needed to quench Faraday's desire.

His time expired October 7, 1812, and he became a journeyman bookbinder under a disagreeable master, so that he longed more than ever to be free. To Huxtable he wrote: "With respect to the progress of the sciences I know but little, and am now likely to know still less; indeed, as long as I stop in my present situation (and I see no chance of getting out of it just yet), I must resign philosophy entirely to those who are more fortunate in the possession of time and means." He is in "very low spirits". At last he took the bold step of writing to Sir Humphry Davy, expressing his wishes, and begging that if opportunity came in his way the great man would favour his views. At the same time he sent the bound notes of Davy's lectures. Davy's reply (December 24, 1812) was "immediate, kind, and favourable". He was obliged to go out of town till the end of January, but he would see Faraday on his return. The interview took place at the Royal Institution. Davy advised him to stick to his business as a bookbinder, and promised to give him the work of the Institution as well as his own. Faraday had the wisdom to receive in a proper spirit advice which was both kindly meant and disinterested, and also the patience to await his opportunity. Nor had he to wait long, for in March the incident occurred which was to be the turning-point in his fortunes. The family were then living in Weymouth Street (No. 18), Portland Place, where James Faraday had died in 181o. One night as Faraday was undressing, the rattle of wheels awoke the echoes of the quiet street, a carriage and pair drew up at No. i8, and the footman having knocked loudly at the door delivered a note from Sir H. Davy. The next morning an interview took place, at which Davy offered Faraday the place of assistant in the laboratory of the Royal Institution, at a salary of twenty-five shillings a week, with two rooms at the top of the house. The late assistant had been summarily dismissed, and Faraday was duly installed in his post on March I.

In the autumn of this year he set forth with Sir H. Davy and his wife on their Continental tour. This pilgrimage—the opening of a new passage in Faraday's life—though in itself of short duration, by introducing him to scenes and people wholly new had the effect of widening his mind and correcting some of his ideas. Davy wished to travel, and had offered to take Faraday with him as his amanuensis. To Faraday, who had never travelled more than a few miles out of London, every mile of progress was a revelation. He kept a full journal of the tour, which Bence Jones says "is remarkable for the minuteness of the description of all he saw".

At Paris Davy's high name carried them everywhere, and Faraday was a spectator, as well as assistant and chronicler, at the interviews and experiments between Davy and the great scientific men of the capital. From Paris, where they stayed two months, the travellers proceeded through France to Montpellier, thence to Nice, and from Nice they crossed the Alps to Turin. The next place of lengthened stay was Florence, whence they went to Rome.

Faraday's powers of observation, exercised to the full, allowed nothing to escape. We get word-portraits of the postilion in jack-boots; the thin pigs of Morlaix (capable of outrunning their post-horses for a mile); and a thumb-nail sketch of the First Napoleon visiting the Senate in full state—"He was sitting in one corner of his carriage, covered and almost hidden from sight by an enormous robe of ermine, and his face over-shadowed by a tremendous plume of feathers that descended from a velvet hat." At Florence they made the "grand experiment of burning the diamond" by the sun's heat in a globe filled with oxygen gas by means of the Grand Duke's gigantic lens, and proved that the invisible result was carbonic acid. They visited and examined the springs of inflammable gas at Pietra Mada and the molten minerals of Vesuvius. The lighter side of the tour is illustrated by the Carnival Week at Rome, into the follies of which he entered with full enjoyment, "and between us we puzzled them mightily, and we both came away well entertained."

On his return to England in 11815 Faraday was re-engaged at the Royal Institution as assistant in the laboratory and mineralogical collection and superintendent of apparatus, at a salary of thirty shillings a week and apartments. In his love for knowledge and his earnest search after it he rejoices at "the glorious opportunity I enjoy of improving in the knowledge of chemistry and the sciences with Sir H. Davy"—tempered by "I have learned just enough to perceive my ignorance", and "the little knowledge I have gained makes me wish to know more". His appreciation of Davy's genius and powers was unbounded. He had compared him with the French philosophers whilst helping him in his discovery of iodine; and he was just about to see him engage in those researches on fire-damp and flame, which ended in the glorious invention of the Davy lamp, and gave to Davy a popular reputation even beyond that which he had gained in science by the greatest of all his discoveries—potassium. Part of Faraday's duties was to copy Davy's rough MSS., and he carefully preserved the originals and bound them into volumes.

On January 17, 1816, Faraday gave his first lecture at the City Philosophical Society, the subject being the general properties of matter. He followed this up with six more lectures dealing mainly with chemical subjects during the year. These his earliest lectures he wrote out with great care, and the subjects—the unity, relationships, and nature of matter and force—were those which occupied his thoughts to the end of his life. In the same year he published his first contribution to science—a paper on an analysis of caustic lime from Tuscany—in the Quarterly Journal of Science. His time was now fully occupied with his duties, his experiments, and what he terms "school" work, i.e. the continuation of the system of self-teaching which he had begun long before, so that he had little spare time for social engagements, and had to plead work to clear himself of the charge of "deserting his old friends for new ones". In 1818 (says Tyndall) he experimented on "Sounding Flames", correcting and completing with great acuteness a previous investigation by the elder De la Rive. In 182o he sent to the Royal Society a paper On Two New Compounds of Chlorine and Carbon, and on a New Compound of Iodine, Carbon, and Hydrogen. This was the first paper of his to be honoured with a place in the Philosophical Transactions.

The year 1821 was that of Faraday's marriage to Sarah Barnard, the daughter of Mr. Barnard, a working silversmith of Paternoster Row, and the same year marks the beginning of Faraday's career as an independent discoverer. His first notable discovery, and his first success in electro-magnetic research—the field of his most fruitful discoveries—was the "production of the rotation of magnets and of wires conducting the electric current round each other". This is the descriptive title; it is filled shortly, the electro-magnetic rotations. He had resolved to investigate the subject, and as a means of disciplining himself for the work wrote a history of electro-magnetism down to that date, which was published in the Annals of Philosophy: During the writing of this sketch Faraday repeated for his own satisfaction almost all the experiments which he described. As a result he was led to the discovery of the true nature of the movement, and on Christmas Day, 1821, he led his wife into the laboratory and showed her for the first time the revolution of a magnetic needle round an electric current.

His next discovery of importance—the liquefaction of chlorine gas, in 1823—was the outcome of an inquiry into the nature of a substance which had long been regarded as the chemical element of chlorine in a solid state, but which Davy in 1810 had proved to be hydrate of chlorine, that is, a compound of chlorine and water. Faraday had analyzed this substance and written an account of its composition. This account he had submitted to Davy, who suggested the heating of the hydrate under pressure in a sealed glass tube. This was done. The hydrate fused at a blood-heat, the tube became filled with a yellow atmosphere, and was found to contain two liquid substances. Dr. Paris, the biographer of Davy, relates that he happened to enter the laboratory while Faraday was at work, and seeing the oily liquid in the tube, rallied the experimenter upon his carelessness in using soiled vessels. Later on in the day, Faraday filed off the end of the tube, whereupon the contents exploded and the oily matter vanished. The next morning Dr. Paris received the following note from Faraday:—

"Dear Sir,—The oil  you noticed yesterday turns out to be liquid chlorine.

"Yours faithfully,

M. FARADAY.

He afterwards found that the gas could be liquefied by compression with a, syringe. The success of this experiment led to similar trials with other gases, and with a like result in each case. The results of these experiments, says Tyndall, went to prove that all gases are but the vapours of liquids possessing very low boiling-points. A. paper on the first investigation was read before the Royal Society on April 10, 1823, and published in Faraday's name in the Philosophical Transactions. Twenty years later Faraday again took up this subject and considerably expanded its limits. In 1825 the Philosophical Transactions  contained a paper by Faraday On New Compounds of Carbon and Hydrogen';  this paper contained the announcement of his important discovery of the substance called Benzol, "which, in the hands of modem chemists, has become the foundation of our splendid aniline dyes."

In February, 1825, Faraday's position at the Royal Institution underwent a change, and from being merely the assistant of Sir H. Davy and Professor Brande he was, on the former's recommendation, appointed by the managers Director of the Laboratory; at the same time, "because of his occupation in research," he was relieved of the duty of acting as chemical assistant at the lectures. His salary at this time was 100 a year. In January of the previous year he had been elected a Fellow of the Royal Society.

We now come to the greatest of Faraday's discoveries—the discovery of Magneto-Electricity and the production of Induced Currents. His notebook for 1822 contained this memorandum: "Convert magnetism into electricity." This, the relation of the magnet and the electric current, was the problem which he had set himself to solve, which he was to ponder for the ensuing ten years, and which during that time and while following up other lines of research, he was never actually to lose touch with. It was the problem which hinged on to his discovery of the magnetic rotations, as that discovery had hinged upon the discovery of Oersted. It had been found possible to produce magnetism from electricity—why, then, should not the converse be true?

Tyndall reminds us of Faraday's characteristic —that he never could work from the experiments of others, however clearly described—he hardly trusted himself to reason upon an experiment that he had not seen. This was why, in the autumn of 1831, he began to repeat the experiments with electric currents which, up to that time, had produced no positive results; and that he succeeded where others had failed was due, in a, great measure, to a power which he possessed in an extraordinary degree. "He united" (says Tyndall) "vast strength with perfect flexibility. His momentum was that of a river, which combines weight and directness with the ability to yield to the flexures of its bed."

We must pass quickly over the description of the manner in which the actual discovery of induced currents was brought about—the two wires, one "living", the other "dead"—the induced current showing itself in the dead wire by the movement of the galvanometer needle to which it was attached; but such movements (for there were two kinds) being limited to the moments of switching on and switching off the current, between which,, and while the current was flowing  through the first wire, the needle remained motionless. The movement in either case was very slight, and the direction  of the movement when the circuit was interrupted was contrary to that observed on the completion of the circuit. Slight and momentary as these movements were they sufficed to show Faraday that "the battery current through the one wire did in reality induce a similar current through the other; but that it continued for an instant only, and partook more of the nature of the electric wave from a common Leyden jar than of the current from a voltaic battery". Further experiments with differently constructed apparatus went to confirm this conclusion, and to show that these induced currents existed only when the "living" and "dead" wires were in motion; when neither was moved, no matter how close their proximity might be, no induced current was generated.

His next step, as his notebook entry of 1822 already quoted showed, was to discover the method of inducing electricity from the magnet (the converse of what he had already accomplished). He experimented with a welded iron ring surrounded by two separate coils of covered wire, and having magnetized the iron ring by an induced current sent into one section of the wire, he found the galvanometer needle connected with the other section sent spinning round several times. As before, the action was limited to the onset, or the closing, of the current—or in other words, to the magnetization or demagnetization of the ring. The effects obtained with the welded ring were also obtained with straight bars of iron, or, abandoning the use of iron, by merely thrusting a permanent steel magnet into a coil of wire. "A rush of electricity through the coil accompanied the insertion of the magnet; an equal rush in the opposite direction accompanied its withdrawal. The precision with which Faraday describes these results, and the completeness with which he defines the boundaries of his facts," says Tyndall, "are wonderful. The magnet, for example, must not be passed quite through the coil, but only half through; for if passed wholly through, the needle is stopped as by a blow, and then he shows how this blow results from a reversal of the electric wave in the helix (coil). He next operated with the powerful magnet of the Royal Society, and obtained with it, in an exalted degree, all the foregoing phenomena."

He was now prepared to attack a problem which had puzzled and baffled the greatest investigators abroad and at home—the meaning of Arago's discovery of 1824 that a disk of non-magnetic metal had the power of bringing a vibrating magnetic needle suspended over it rapidly to rest; and that on causing the disk to rotate the magnetic needle rotated along with it. "Faraday saw mentally the rotating disk, under the operation of the magnet, flooded with his induced currents, and from the known laws of interaction between currents and magnets he hoped to deduce the motion observed by Arago. That hope he realized, showing by actual experiment that when his disk rotated currents passed through it, their position and direction being such as must, in accordance with the established laws of electro-magnetic action, produce the observed rotation." He spun a disk connected with a galvanometer between the poles of the great magnet of the Royal Society, and thereby obtained a constant flow of electricity—the direction of the current being determined by the direction of the motion, the current being reversed when the rotation was reversed. "He now states the law which rules the production of currents in both disks and wires, and in so doing uses, for the first time, a phrase which has since become famous. When iron filings are scattered over a magnet, the particles of iron arrange them selves in certain determinate lines called magnetic curves. In 1831, Faraday for the first time called these curves 'lines of magnetic force'; and he showed that to produce induced currents neither approach to nor withdrawal from a magnetic source, or centre, or pole, was essential, but that it was only necessary to cut appropriately the lines of magnetic force."

Faraday

LECTURING AT THE ROYAL INSTITUTION IN 1835.


The familiar arrangement of the iron filings upon the magnet, then, represented "lines of magnetic force". Cut these lines of force and you produce induced currents: here was the solution of the problem of the rotating disk and the following magnetic needle. The mind of Faraday expands with the idea. The earth itself is a great magnet—cut its lines of magnetic force, and induced currents will be set up. He spins a copper disk across the earth's lines of force, producing such currents; he describes the portions of the disk wherein no current could be produced by its motion. "He plays with the earth," says Tyndall, "as with a magnetic toy. He sees the invisible lines Along which its magnetic action is exerted, and sweeping his magician's wand across these lines evokes this new power."

In the short account we have given of his work we have scarcely advanced beyond the threshold of his discoveries in that department of science which occupied the best part of his working life; and we have only space left to mention his experiments in Electric Conduction, in which he proved that the self-same substance, conducts, or refuses to conduct, According as it is liquid or solid—the current, for example, which passes through water cannot pass through ice—and so on; his reformation of the technical language of electrical science by the invention of terms which have since become the terms of everyday use; his invention of the "Voltameter", based upon the measurement of the quantity of electricity which passes through a liquid by the quantity of gas evolved during the operation; his masterly demonstration of the source of the power in the voltaic pile, in which he showed that chemical action, and not mere contact of different metals, was the true source of voltaic power; and, finally, his important inquiry into the means by which electrical power is transmitted. In regard to the last-named subject, Faraday, says Tyndall, was always perplexed and bewildered by the idea of action at a distance:  he contended that there must be a medium. In the case of the decomposition of a fluid he was certain that the current was propagated from particle to particle, and he became more and more impressed with the conviction that ordinary electric induction was also transmitted and sustained by the action of contiguous particles. "In our own day the idea of action at a distance is almost lost in the background, and it is held that both electric and magnetic actions, like those of light, are transmitted through an all-embracing medium."

In 1841 Faraday's health broke down, and for three years he did nothing—not even "reading on science". He went to Switzerland with his wife and brother-in-law.

In November, 1845, returning to England, he announced a new discovery under the title of The Magnetization of Light, and the Illumination of the Lines of Electric Force—which Tyndall translates into "the rotation of the plane of polarization by magnets and by electric currents", and in which he demonstrated the relations between magnetic force and light; but the experiments and their results cannot be described here. It was in this research that Faraday employed with success the famous "heavy glass" which he had made many years before at the Royal Institution. This heavy glass also played an important part in his next discovery—that of "Diamagnetism"—which followed quickly upon the last. By "diamagnetic" Faraday meant those bodies which were repelled by the poles of a magnet—as distinguished from those which were attracted, for which the term "magnetic" was reserved. Finding by experiment that a bar of his heavy glass was repelled when placed between the poles of a magnet, he proceeded to experiment with all kinds of substances—crystals, powders, resins, oils, salts, vegetable and animal tissues, aqueous solutions, etc.—and found that no known solid or liquid was insensible to magnetic power when it was developed in sufficient strength. Many of his experiments, especially those with crystals and flames, were extremely beautiful. He filled soap-bubbles with oxygen gas and found them strongly amenable to magnetic influence. He finally tried to find a "magnetic zero", or a substance which should be neutral to the magnet when excited to its uttermost. "After a series of experiments of the rarest beauty and precision" (says Tyndall) "he came to the conclusion that nitrogen was 'like space itself'—neither magnetic nor diamagnetic."

In old age, Lady Pollock describes him on his return to his lecture table in the Royal Institution after an absence caused by illness:—

"As soon as his presence was recognized, the whole audience rose simultaneously and burst into a spontaneous utterance of welcome, loud end long. Faraday stood in acknowledgment of this enthusiastic greeting, with his fine head slightly bent; . . . a certain resemblance to the pictures and busts of Lord Nelson . . . was always observable in his countenance."

Honours and appointments were freely bestowed upon Faraday following his discovery of magneto-electricity. In 1832 Oxford made him an honorary D.C.L., and at the same time he received the Copley Medal from the Royal Society—the highest award it had to bestow. In 1836 he was nominated by the Crown a Member of the Senate of the University of London, retaining this position for twenty-seven years.

Faraday House

HOUSE AT HAMPTON COURT.


From the date of his marriage up till 1858 Faraday and his wife had continued to reside at the Royal Institution; but in the latter year the Queen placed at his disposal for life a comfortable house at Hampton Court, on the Green. Faraday was delighted with this mark of Royal recognition, which it is said was conferred at the instance of the Prince Consort, and under his direction, though his name never appeared in the correspondence. The Hampton Court house remained the home of Faraday till his death.

His decline was heralded by a loss of memory, and this was followed by other symptoms of decaying power. "Barlow," he said to the friend who had long directed with him the affairs of the Royal Institution, but who was then half paralysed—"Barlow, you and I are waiting; that is what we have to do now; and we must try to do it patiently." On August 25, 1867, Faraday peacefully expired, seated in his armchair in his study. He was buried in Highgate Cemetery.

"Nature, not education, made Faraday strong and refined," wrote Tyndall. "A favourite experiment of his own was representative of himself. He loved to show that water, in crystallizing, excluded all foreign ingredients, however intimately they might be mixed with it. Out of acids, alkalis, or saline solutions, the crystal came sweet and pure. By some such natural process in the formation of this man, beauty and nobleness coalesced, to the exclusion of everything vulgar and low."

"His standard of duty," says Bence Jones, in conclusion, "was supernatural. It was not founded upon any intuitive ideas of right and wrong; nor was it fashioned upon any outward expediencies of time and place; but it was formed entirely on what he held to be the revelation of the will of God in the written Word, and (throughout all his life his faith led him to act up to the very letter of it."