Kitabı oku: «Michael Faraday», sayfa 7

In this day, when so many allow their names to be used for offices of which they never intended to discharge the duties, the following letter may convey an appropriate lesson: —

"Royal Institution, Oct. 17th, 1849.

"My dear Percy,

"I cannot be on the committee; I avoid everything of that kind, that I may keep my stupid mind a little clear. As to being on a committee and not working, that is worse still. * * *

"Ever yours and Mrs. Percy's,

"M. Faraday."

It is well known that he waged implacable war with the Spiritualists. Eighteen years ago tables took to spinning mysteriously under the fingers of ladies and gentlemen who sat or stood around the animated furniture; much was said about a new force, much too about strange revelations from another sphere, but Faraday made a simple apparatus which convinced him and most others that the tables moved through the unconscious pressure of the hands that touched them. The account of this will be found in the Athenæum of July 2, 1853. Three weeks afterwards he wrote to his friend Schönbein: "I have not been at work except in turning the tables upon the table-turners, nor should I have done that, but that so many inquiries poured in upon me, that I thought it better to stop the inpouring flood by letting all know at once what my views and thoughts were. What a weak, credulous, incredulous, unbelieving, superstitious, bold, frightened, – what a ridiculous world ours is, as far as concerns the mind of man! How full of inconsistencies, contradictions, and absurdities it is!" But the believers in these occult phenomena, some of them holding high positions about the Court, would not let him alone; and there are many indications of the annoyance and irritation they caused him. He declined to meet the professors of the mysterious art, and the following letter will serve to show the way in which he regarded them: —

"Royal Institution, Nov. 1, 1864.

"Sir,

"I beg to thank you for your papers, but have wasted more thought and time on so-called spiritual manifestation than it has deserved. Unless the spirits are utterly contemptible, they will find means to draw my attention.

"How is it that your name is not signed to the testimony that you give? Are you doubtful even whilst you publish? I've no evidence that any natural or unnatural power is concerned in the phenomena that requires investigation or deserves it. If I could consult the spirits, or move them to make themselves honestly manifest, I would do it. But I cannot, and am weary of them.

"I am, Sir, your obedient Servant,

"M. Faraday."

There was once a strange statement put forth to the effect that Faraday said electricity was life.¹⁵ He himself denied it indignantly; but as most falsehoods are perversions of some truth, this one probably originated in his experiments on the Gymnotus. He felt an intense interest in those marine animals that give shocks, and sought "to identify the living power which they possess, with that which man can call into action from inert matter, and by him named electricity."¹⁶ The most powerful of these is the Gymnotus, or electrical eel, and a live specimen of this creature, forty inches long, was secured by the Adelaide Gallery – a predecessor of the Polytechnic – in the summer of 1838. Four days after its arrival the poor creature lost an eye; for two months it could not be coaxed to eat either meat or fish, worms or frogs; but at last one day it killed and devoured four small fishes, and afterwards swallowed about a fish per diem. It was accustomed to swim round and round the tank, till a live fish was dropped in, when in some cases bending round its victim, it would discharge a shock that made the fish float on its back stunned and ready to be sucked into the jaws of its assailant.

Faraday examined this eel and the water around it, both with his hands and with special collectors of electricity, and satisfied himself not merely of the shock, which was easy enough, but of its power to deflect a galvanometer, to make a magnet, to effect chemical decomposition, and to give a spark. His account of the experiments terminates with some speculations on the connection of this animal electricity with nervous power; but there the matter rested. His own views were thus expressed to his friend Dumas: – "As living creatures produce heat, and a heat certainly identical with that of our hearths, why should they not produce electricity also, and an electricity in like manner identical with that of our machines? But if the heat produced during life, and necessary to life, is not life after all, why should electricity itself be life? Like heat, like chemical action, electricity is an implement of life, and nothing more."

Whether the belief that electricity is life would be inconsistent with the Christian faith or not, it is clear that when an infidel preacher asserts that Faraday held such an opinion, his assertion will influence few who are not already disposed to Materialism. Far more damaging is it to the cause of religion when her ministers repeat the assumption of the infidel that those who study the truths of nature are particularly prone to disbelieve. Yet such statements have been made, even with reference to Faraday. I have it on the best authority that one of the leading clergymen of the day, preaching on a special occasion from Peter's words, "The elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up," spoke in antagonism to scientific men, alluding to Faraday by name, and to his computation of the tremendous electrical forces that would be produced by sundering the elements of one drop of water. "They shall be confuted by their own element – fire," added the preacher, careless of the conclusion which his audience might legitimately draw from such a two-edged argument. The accuser of the men of science was much astonished when told after his sermon, by a brother clergyman, that Faraday and other eminent physicists of the day were believers in a divine revelation.

It may be doubted whether Faraday ever tried to form a definite idea of the relation in which the physical forces stand to the Supreme Intelligence, as Newton did, or his own friend Sir John Herschel; nor did he consider it part of his duty as a lecturer to look beyond the natural laws he was describing. His practice in this respect has been well described by the Rev. Professor Pritchard:¹⁷– "This great and good man never obtruded the strength of his faith upon those whom he publicly addressed; upon principle he was habitually reticent on such topics, because he believed they were ill suited for the ordinary assemblages of men. Yet on more than one occasion when he had been discoursing on some of the magnificent pre-arrangements of Divine Providence so lavishly scattered in nature, I have seen him struggle to repress the emotion which was visibly striving for utterance; and then, at the last, with one single far-reaching word, he would just hint at his meaning rather than express it. On such occasions he only who had ears to hear, could hear."

In his more familiar lectures to the cadets at Woolwich, however, he more than hinted at such elevated thoughts. In conversation, too, Faraday has been known to express his wonder that anyone should fail to recognize the constant traces of design; and in his writings there sometimes occur such passages as the following: – "When I consider the multitude of associated forces which are diffused through nature – when I think of that calm and tranquil balancing of their energies which enables elements most powerful in themselves, most destructive to the world's creatures and economy, to dwell associated together and be made subservient to the wants of creation, I rise from the contemplation more than ever impressed with the wisdom, the beneficence, and grandeur beyond our language to express, of the Great Disposer of all!"

Faraday's journals abound with descriptions of "nature and human nature." He had evidently a keen eye for the beauties of scenery, and occasionally the objects around him suggested higher thoughts. Here are two instances taken from his notes of a Swiss tour in 1841: —

"Monday, 19th.– Very fine day; walk with dear Sarah on the lake side to Oberhofen, through the beautiful vineyards; very busy were the women and men in trimming the vines, stripping off leaves and tendrils from the fruit-bearing branches. The churchyard was beautiful, and the simplicity of the little remembrance-posts set upon the graves very pleasant. One who had been too poor to put up an engraved brass plate, or even a painted board, had written with ink on paper the birth and death of the being whose remains were below, and this had been fastened to a board, and mounted on the top of a stick at the head of the grave, the paper being protected by a little edge and roof. Such was the simple remembrance, but Nature had added her pathos, for under the shelter by the writing a caterpillar had fastened itself, and passed into its deathlike state of chrysalis, and, having ultimately assumed its final state, it had winged its way from the spot, and had left the corpse-like relics behind. How old and how beautiful is this figure of the resurrection! Surely it can never appear before our eyes without touching the thoughts."

"August 12th, Brienz Lake.– George and I crossed the lake in a boat to the Giessbach – he to draw, and I to saunter… This most beautiful fall consists of a fine river, which passes by successive steps down a very deep precipice into the lake. In some of these steps there is a clear leap of water of 100 feet or more, in others most beautiful combinations of leap, cataract, and rapid, the finest rocks occurring at the sides and bed of the torrent. In one part a bridge passes over it. In another a cavern and a path occur under it. To-day every fall was foaming from the abundance of water, and the current of wind brought down by it was in some parts almost too strong to stand against. The sun shone brightly, and the rainbows seen from various points were very beautiful. One at the bottom of a fine but furious fall was very pleasant. There it remained motionless, whilst the gusts and clouds of spray swept furiously across its place, and were dashed against the rock. It looked like a spirit strong in faith and stedfast in the midst of the storm of passions sweeping across it; and though it might fade and revive, still it held on to the rock as in hope and giving hope; and the very drops which in the whirlwind of their fury seemed as if they would carry all away, were made to revive it and give it greater beauty.

"How often are the things we fear and esteem as troubles made to become blessings to those who are led to receive them with humility and patience."

In concluding this section it may be well to string together a few gems from Faraday's lectures or correspondence, though they are greatly damaged by being torn away from their original setting: —

"After all, though your science is much to me, we are not friends for science sake only, but for something better in a man, something more important in his nature, affection, kindness, good feeling, moral worth; and so, in remembrance of these, I now write to place myself in your presence, and in thought shake hands, tongues, and hearts together." This was addressed to Schönbein.

"I should be glad to think that high mental powers insured something like a high moral sense, but have often been grieved to see the contrary: as also, on the other hand, my spirit has been cheered by observing in some lowly and uninstructed creature such a healthful and honourable and dignified mind as made one in love with human nature. When that which is good mentally and morally meet in one being, that that being is more fitted to work out and manifest the glory of God in the creation, I fully admit."

"Let me, as an old man who ought by this time to have profited by experience, say that when I was younger I found I often misinterpreted the intentions of people, and found they did not mean what at the time I supposed they meant; and further, that as a general rule, it was better to be a little dull of apprehension when phrases seemed to imply pique, and quick in perception when, on the contrary, they seemed to imply kindly feeling. The real truth never fails ultimately to appear; and opposing parties, if wrong, are sooner convinced when replied to forbearingly, than when overwhelmed."

"Man is an improving animal. Unlike the animated world around him, which remains in the same constant state, he is continually varying; and it is one of the noblest prerogatives of his nature, that in the highest of earthly distinctions he has the power of raising and exalting himself continually. The transitory state of man has been held up to him as a memento of his weakness: to man degraded it may be so with justice; to man as he ought to be it is no reproach; and in knowledge, that man only is to be contemned and despised who is not in a state of transition."

"It is not the duty or place of a philosopher to dictate belief, and all hypothesis is more or less matter of belief; he has but to give his facts and his conclusions, and so much of the logic which connects the former with the latter as he may think necessary, and then to commit the whole to the scientific world for present, and, as he may sometimes without presumption believe, for future judgment."

SECTION IV
HIS METHOD OF WORKING

It is on record that when a young aspirant asked Faraday the secret of his success as a scientific investigator, he replied, "The secret is comprised in three words – Work, Finish, Publish."

Each of these words, we may be sure, is full of meaning, and will guide us in a useful inquiry.

Already in the "Story of his Life" we have caught some glimpses of the philosopher at work in his laboratory; but before looking at him more closely let us learn from a foreigner with what feelings to enter a place that is hallowed by so many memories sacred in the history of science. Professor Schönbein, of Basle, who visited England in 1840, says: "During my stay in London, I once worked with Faraday for a whole day long in the laboratory of the Royal Institution, and I cannot forbear to say that this was one of the most enjoyable days that I ever spent in the British capital. We commenced our day's work with breakfast; and when that was over, I was supplied with one of the laboratory dresses of my friend, which, when I was presented in it to the ladies, gave occasion to no little amusement, as the dimensions of Faraday are different from those of my precious body.

"To work with a man like Faraday was in itself a great pleasure; but this pleasure was not a little heightened in doing so in a place where such grand secrets of nature had been unfolded, the most brilliant discoveries of the century had been made, and entirely new branches of knowledge had been brought forth. For the empty intellect circumstances of this nature are indeed of little special value; but they stand in quite another relation to our power of imagination and inner nature.

"I do not deny that my surroundings produced in me a very peculiar feeling; and whilst I trod the floor upon which Davy had once walked – whilst I availed myself of some instrument which this great discoverer had himself handled – whilst I stood working at the very table at which the ever-memorable man sought to solve the most difficult problems of science, at which Faraday enticed the first sparks out of the magnet, and discovered the most beautiful laws of the chemical action of current electricity, I felt myself inwardly elevated, and believed that I myself experienced something of the inbreathing of the scientific spirit which formerly ruled there with such creative power, and which still works on."¹⁸

The habit of Faraday was to think out carefully beforehand the subject on which he was working, and to plan his mode of attack. Then, if he saw that some new piece of apparatus was needed, he would describe it fully to the instrument maker with a drawing, and it rarely happened that there was any need of alteration in executing the order. If, however, the means of experiment existed already, he would give Anderson a written list of the things he would require, at least a day before – for Anderson was not to be hurried. When all was ready, he would descend into the laboratory, give a quick glance round to see that all was right, take his apron from the drawer, and rub his hands together as he looked at the preparations made for his work. There must be no tool on the table but such as he required. As he began, his face would be exceedingly grave, and during the progress of an experiment all must be perfectly quiet; but if it was proceeding according to his wish, he would commence to hum a tune, and sometimes to rock himself sideways, balancing alternately on either foot. Then, too, he would often talk to his assistant about the result he was expecting. He would put away each tool in its own place as soon as done with, or at any rate when the day's work was over, and he would not unnecessarily take a thing away from its place: thus, if he wanted a perforated cork, he would go to the drawer which contained the corks and cork-borers, make there what he wanted, replace the borers, and shut the drawer. No bottle was allowed to remain without its stopper; no open glass might stand for a night without a paper cover; no rubbish was to be left on the floor; bad smells were to be avoided if possible; and machinery in motion was not permitted to grate. In working, also, he was very careful not to employ more force than was wanted to produce the effect. When his experiments were finished and put away, he would leave the laboratory, and think further about them upstairs.

This orderliness and this economy of means he not only practised himself, but he expected them also to be followed by any who worked with him; and it is from conversation with these that I have been enabled to give this sketch of his manner of working.¹⁹

This exactness was also apparent in the accounts he kept with the Royal Institution and Trinity House, in which he entered every little item of expenditure with the greatest minuteness of detail.

It was through this lifelong series of experiments that Faraday won his knowledge and mastered the forces of nature. The rare ingenuity of his mind was ably seconded by his manipulative skill, while the quickness of his perceptions was equalled by the calm rapidity of his movements.

He had indeed a passion for experimenting. This peeps out in the preface to the second edition of his "Chemical Manipulation," where he writes, "Being intended especially as a book of instruction, no attempts were made to render it pleasing, otherwise than by rendering it effectual; for I concluded that, if the work taught clearly what it was intended to inculcate, the high interest always belonging to a well-made or successful experiment would be abundantly sufficient to give it all the requisite charms, and more than enough to make it valuable in the eyes of those for whom it was designed."

He could scarcely pass a gold leaf electrometer without causing the leaves to diverge by a sudden flick from his silk handkerchief. I recollect, too, his meeting me at the entrance to the lecture theatre at Jermyn Street, when Lyon Playfair was to give the first, or one of the first lectures ever delivered in the building. "Let us go up here," said he, leading me far away from the central table. I asked him why he chose such an out-of-the-way place. "Oh," he replied, "we shall be able here to find out what are the acoustic qualities of the room."

The simplicity of the means with which he made his experiments was often astonishing, and was indeed one of the manifestations of his genius.

A good instance is thus narrated by Sir Frederick Arrow. "When the electric light was first exhibited permanently at Dungeness, on 6th June, 1862, a committee of the Elder Brethren, of which I was one, accompanied Faraday to observe it. We dined, I think, at Dover, and embarked in the yacht from there, and were out for some hours watching it, to Faraday's great delight – (a very fine night) – and especially we did so from the Varne lightship, about equidistant between it and the French light of Grisnez, using all our best glasses and photometers to ascertain the relative value of the lights: and this brings me to my story. Before we left Dover, Faraday, with his usual bright smile, in great glee showed me a little common paper box, and said, 'I must take care of this; it's my special photometer,' – and then, opening it, produced a lady's ordinary black shawl-pin, – jet, or imitation perhaps, – and then holding it a little way off the candle, showed me the image very distinct; and then, putting it a little further off, placed another candle near it, and the relative distance was shown by the size of the image. He lent me this afterwards when we were at the Varne lightship, and it acted admirably; and ever since I have used one as a very convenient mode of observing, and I never do so but I think of that night and dear good Faraday, and his genial happy way of showing how even common things may be made useful." After this Faraday modified his glass-bead photometer, and he might be seen comparing the relative intensity of two lights by watching their luminous images on a bead of black glass, which he had threaded on a string, and was twirling round so as to resolve the brilliant points into circles of fainter light; or he fixed the black glass balls on pieces of cork, and, attaching them to a little wheel, set them spinning for the same purpose. Some of these beads are preserved by the Trinity House, with other treasures of a like kind, including a flat piece of solder of an irregular oval form, turned up at one side so as to form a thumb-rest, and which served the philosopher as a candlestick to support the wax-light that he used as a standard. The museum of the Royal Institution contains a most instructive collection of his experimental apparatus, including the common electrical machine which he made while still an apprentice at Riebau's, and the ring of soft iron, with its twisted coils of wire isolated by calico and tied with common string, by means of which he first obtained electrical effects from a magnet.

In lecturing to the young he delighted to show how easily apparatus might be extemporized. Thus, in order to construct an electrical machine he once inverted a four-legged stool to serve for the stand, and took a white glass bottle for the cylinder. A cork was fitted into the mouth of this bottle, and a bung was fastened with sealing-wax to the other end: into the cork was inserted a handle for rotating the bottle, and in the centre of the bung was a wooden pivot on which it turned; while with some stout wire he made crutches on two of the legs of the stool for the axles of this glass cylinder to work upon. The silk rubber he held in his hand. A japanned tin tea-canister resting on a glass tumbler formed the conductor, and the collector was the head of a toasting fork. With this apparently rough apparatus he exhibited all the rudimentary experiments in electricity to a large audience.

Wishing to carry home in good condition a flower that had been given him, he rolled a piece of writing-paper round a cork, tied it tightly with string, and filled the little tube with water. He had thus a perfectly efficient bouquet-holder.

A lady, calling on his wife, happened to mention that a needle had been once broken into her foot, and she did not know whether it had been all extracted or not. "Oh!" said Faraday, "I will soon tell you that," – and taking a finely suspended magnetic needle, he held it close to her foot, and it dipped to the concealed iron.

On this subject Schönbein has also some good remarks. "The laboratory of the Institution is indeed efficiently arranged, though anything but large and elaborately furnished. And yet something extraordinary has happened in this room for the extension of the limits of knowledge; and already more has been done in it than in many other institutions where the greatest luxury in the supply of apparatus prevails, and where there is the greatest command of money. But when men work with the creative genius of a Davy, and the intuitive spirit of investigation and the wealth of ideas of a Faraday, important and great things must come to pass, even though the appliances at command should be of so limited a character. For the experimental investigator of nature, it is especially desirable that, according to the kind of his researches, he should have at command such and such appliances, that he should possess a 'philosophical apparatus,' a laboratory, &c.; but for the purpose of producing something important, of greatly widening the sphere of knowledge, it in no way follows that a superfluity of such things is necessary to him… He who understands how to put appropriate questions to Nature, generally knows how to extract the answers by simple means; and he who wants this capacity will, I fear, obtain no profitable result, even though all conceivable tools and apparatus may be ready to his hand."

Nor did Faraday require elaborate apparatus to illustrate his meaning. Steaming up the Thames one July day in a penny boat, he was struck with the offensiveness of the water. He tore some white cards into pieces, wetted them so as to make them sink easily, and dropped them into the river at each pier they came to. Their sudden disappearance from sight, though the sun was shining brightly, was proof enough of the impurity of the stream; and he wrote a letter to the Times describing his observations, and calling public attention to the dangerous state of the river.²⁰ At a meeting of the British Association he wished to explain the manner in which certain crystallized bodies place themselves between the poles of an electro-magnet: two or three raw potatoes furnished the material out of which he cut admirable models of the crystals. Wishing to show the electrical nature of gun-cotton, he has been known to lay his watch upon the table, balance on it a slender piece of wood, and, charging a morsel of the gun-cotton by drawing it along his coat sleeve, cause the wood to revolve towards the electric fibres.

"An artist was once maintaining that in natural appearances and in pictures, up and down, and high and low, were fixed indubitable realities; but Faraday told him that they were merely conventional acceptations, based on standards often arbitrary. The disputant could not be convinced that ideas which he had hitherto never doubted had such shifting foundations. 'Well,' said Faraday, 'hold a walking-stick between your chin and your great toe; look along it and say which is the upper end.' The experiment was tried, and the artist found his idea of perspective at complete variance with his sense of reality; either end of the stick might be called 'upper,' – pictorially it was one, physically it was the other."

Faraday's manner of experimenting may be further illustrated by the recollections of other friends who have had the opportunity of watching him at work.

Mr. James Young, who was in the laboratory of University College in 1838, thus writes: – "About that time Professor Graham had got from Paris Thilorier's apparatus for producing liquid and solid carbonic acid; hearing of this, Mr. Faraday came to Graham's laboratory, and, as one might expect, showed great interest in this apparatus, and asked Graham for the loan of it for a Friday evening lecture at the Royal Institution, which of course Graham readily granted, and Faraday asked me to come down to the Institution and give him the benefit of my experience in charging and working the apparatus; so I spent a long evening at the Royal Institution laboratory. There was no one present but Faraday, Anderson, and myself. The principal thing we did was to charge the apparatus and work with the solid carbonic acid, Mr. Faraday working with great activity; his motions were wonderfully rapid; and if he had to cross the laboratory for anything, he did not walk at an ordinary step, but ran for it, and when he wanted anything he spoke quickly. Faraday had a theory at that time that all metals would become magnetic if their temperature were low enough; and he tried that evening some experiments with cobalt and manganese, which he cooled in a mixture of carbonic acid and ether, but the results were negative."

Among the deep mines of the Durham coal-field is one called the Haswell Colliery. One Saturday afternoon, while the men were at work in it as usual, a terrible explosion occurred: it proceeded from the fire-damp that collects in the vaulted space that is formed in old workings, when the supporting pillars of coal are removed and the roof falls in: the suffocating gases rushed along the narrow passages, and overwhelmed ninety-five poor fellows with destruction. Of course there was an inquiry, and the Government sent down to the spot as their commissioners Professor Faraday and Sir Charles Lyell. The two gentlemen attended at the coroner's inquest, where they took part in the examination of the witnesses; they inspected the shattered safety-lamps; they descended into the mine, spending the best part of a day in the damaged and therefore dangerous galleries where the catastrophe had occurred, and they did not leave without showing in a practical form their sympathy with the sufferers. When down in the pit, an inspector showed them the way in which the workmen estimated the rapidity of the ventilation draught, by throwing a pinch of gunpowder through the flame of a candle, and timing the movement of the little puff of smoke. Faraday, not admiring the free and easy way in which they handled their powder, asked where they kept their store of it, and learnt that it was in a large black bag which had been assigned to him as the most comfortable seat they could offer. We may imagine the liveliness with which he sprang to his feet, and expostulated with them on their culpable carelessness.