THE Chair of Experimental Physics in the University of Cambridge was founded by a Grace of the Senate on the 9th of February 1871.
In October 1870 the Duke of Devonshire, who was Chancellor of the University, had signified his desire to build and furnish a Physical Laboratory for Cambridge. In acting as a member of the Royal Commission on Scientific Education, he had perceived how useful such an institution might be made. It was in connection with the acceptance of this munificent offer that the new professorship was established by the Senate.
The question, who should be the first professor? was for some time attended with anxiety. It was understood that Sir William Thomson had declined to stand, and it was thought uncertain whether Clerk Maxwell could be persuaded to leave the retirement of his country-seat. After some hesitation, arising chiefly from genuine diffidence, he was induced to become a candidate, on the understanding that he might retire at the end of a year, if he wished to do so. His candidature was announced on the 24th of February.[217] There was no opposition, and he was appointed on the 8th of March.
The following letters indicate the part taken by various persons in bringing about this result:—
From the Hon. J. W. Strutt (Lord Rayleigh).
Cambridge, 14th February 1871.
When I came here last Friday I found every one talking about the new professorship, and hoping that you would come. Thomson, it seems, has definitely declined.... There is no one here in the least fit for the post. What is wanted by most who know anything about it is not so much a lecturer as a mathematician who has actual experience in experimenting, and who might direct the energies of the younger Fellows and bachelors into a proper channel. There must be many who would be willing to work under a competent man, and who, while learning themselves, would materially assist him.... I hope you may be induced to come; if not, I don’t know who it is to be. Do not trouble to answer me about this, as I believe others have written to you about it.
From the Rev. E. W. Blore, M.A. (now Vice-Master of Trinity).
14th February 1871.
Many residents of influence are desirous that you should occupy the post, hoping that in your hands this University would hold a leading place in this department. It has, I believe, been ascertained that Sir W. Thomson would not accept the professorship. I mention this lest you should wish to avoid the possibility of coming into the field against him.
Maxwells usual modesty is apparent in the draft of his reply to this letter:—
Glenlair, Dalbeattie, 15th February 1871.
My dear Blore—Though I feel much interest in the proposed Chair of Experimental Physics, I had no intention of applying for it when I got your letter, and I have none now, unless I come to see that I can do some good by it.
... I am sorry Sir W. Thomson has declined to stand. He has had practical experience in teaching experimental work, and his experimental corps have turned out very good work. I have no experience of this kind, and I have seen very little of the somewhat similar arrangements of a class of real practical chemistry. The class of Physical Investigations, which might be undertaken with the help of men of Cambridge education, and which would be creditable to the University, demand, in general, a considerable amount of dull labour which may or may not be attractive to the pupils.
In the Grace of Senate of 9th February, it had been enacted that it should be “the principal duty of the professor to teach and illustrate the laws of Heat, Electricity, and Magnetism; to apply himself to the advancement of the knowledge of such subjects; and to promote their study in the University.”
For some time after his appointment, Maxwell’s principal work was that of designing and superintending the erection of the Cavendish Laboratory.
He inspected the Physical Laboratories of Sir William Thomson at Glasgow and of Professor Clifton at Oxford, in order to embody in the new structure the best features of both of these institutions. But many of the most important arrangements were of his own invention. An account of the Laboratory itself will be found in Nature (vol. X. p. 139); it is sufficient here to say that it would be difficult to imagine a building better adapted to its purpose, or one in the construction of which more provision should be made for possible requirements. In no case was convenience sacrificed to architectural effect, but in both respects the building is a decided success. The architect was Mr. W. M. Fawcett of Cambridge, who appears to have fully appreciated and thoroughly carried out all Professor Maxwell’s suggestions. The contract was given to Mr. Loveday of Kibworth, his tender being recommended by the report of the Syndicate appointed to superintend the building, dated 1st March 1872.
The work of arranging and furnishing the Cavendish Laboratory occupied a considerable time. It was not completed until the spring of 1874, when the practical work of experimenting commenced, and on the 16th of June in that year, the Chancellor formally presented his gift to the University. Sir Charles Lyell and the French astronomer Leverrier were among those who visited the Laboratory and received the honorary degree of LL.D. from the University on that occasion.
The following draft of a letter from Maxwell to the Vice-Chancellor in the previous year affords an interesting illustration of the thorough and business-like manner in which he had addressed himself to these preliminary labours.
To the Vice-Chancellor, Cambridge.
(Draft of a Letter.)
Glenlair, 5th July 1878.
I enclose a provisional list of fixtures and apparatus required for the Laboratory.
At present I am not able to estimate the prices of many of the articles.
Some of them are in the market, and have simply to be ordered; others require to be constructed specially for the Laboratory.
I have begun with a list arranged according to the places and rooms in the Laboratory, but, of course, all small things must be kept in cases, either in the apparatus room, or in the special rooms.
The special duty of the professor of experimental physics is to teach the sciences of heat and electricity, and also to encourage physical research. The Laboratory must therefore contain apparatus for the illustration of heat and electricity, and also for whatever physical research seems most important or most promising.
The special researches connected with heat which I think most deserving of our efforts at the present time are those relating to the elasticity of bodies, and in general those which throw light on their molecular constitution; and the most important electrical research is the determination of the magnitude of certain electric quantities, and their relations to each other.
These are the principles on which I have been planning the arrangement of the Laboratory. But if in the course of years the course of scientific research should he deflected, the plans of work must vary too, and the rooms must be allotted differently.
I agree with you that the income of the Museums must be largely increased in order to meet the demands of this and other new buildings, and I am glad that the University is able to increase it.
It is impossible to procure many of the instruments, as they are not kept in stock, and have to be made to order. Some of the most important will require a considerable amount of supervision during their construction, for their whole value depends on their fulfilling conditions which can as yet be determined only by trial, so that it may be some time before everything is in working order.
Even in 1874, however, there were still manifold desiderata, and the Duke expressed his wish to furnish the Laboratory completely with the necessary apparatus. To carry out this wish was again a work of time, for the Professor would never order an important instrument until he was satisfied that its design and construction were the best that could be obtained. In his annual report to the University in 1877 Professor Maxwell announced that the Chancellor had now “completed his gift to the University, by furnishing the Cavendish Laboratory with apparatus suited to the present state of science;” but at the same time he wrote to the Vice-Chancellor stating that he should reserve to himself the privilege of presenting to the Laboratory such apparatus as the advancement of science might render it desirable for the University to possess. And during the short remainder of his tenure of the professorship he expended many hundreds of pounds in this manner. And already, in the spring of 1874, he had presented to the Laboratory all the apparatus in his own possession. The apparatus provided by the British Association for their Committee on Electrical Standards (see p. 316), was also deposited in the Laboratory, in accordance with a resolution passed at the Edinburgh Meeting of 1871—the apparatus remaining the property of the Association, and subject to the control of the Committee.
While the Laboratory was thus gradually made available, the other work of the professorship went on uninterruptedly from the first. Maxwell gave annual courses of lectures on the subjects prescribed in his commission,[218] commencing with October 1871, when he delivered his inaugural lecture. This and the lecture “On Colour Vision,” given at the Royal Institution shortly after his appointment in the preceding spring, are perhaps the happiest of his literary efforts. Philosophic grasp, scientific clearness, and poetic imagination could hardly be more successfully combined.
The Cambridge lecture (October 1871) sets forth in luminous outline the meaning and tendency of the moment in the evolution of the University of Cambridge, which was marked by the institution of the course of Experimental Physics, and the erection of the Devonshire Laboratory.
The following passage is especially characteristic:—
Science appears to us with a very different aspect after we have found out that it is not in lecture-rooms only, and by means of the electric light projected on a screen, that we may witness physical phenomena, but that we may find illustrations of the highest doctrines of science in games and gymnastics, in travelling by land and by water, in storms of the air and of the sea, and wherever there is matter in motion.
This habit of recognising principles amid the endless variety of their action can never degrade our sense of the sublimity of nature, or mar our enjoyment of its beauty. On the contrary, it tends to rescue our scientific ideas from that vague condition in which we too often leave them, buried among the other products of a lazy credulity, and to raise them into their proper position among the doctrines in which our faith is so assured that we are ready at all times to act on them. Experiments of illustration may be of very different kinds. Some may be adaptations of the commonest operations of ordinary life; others may be carefully arranged exhibitions of some phenomenon which occurs only under peculiar conditions. They all, however, agree in this, that their aim is to present some phenomenon to the senses of the student in such a way that he may associate with it some appropriate scientific idea. When he has grasped this idea, the experiment which illustrates it has served its purpose.
In an experiment of research, on the other hand, this is not the principal aim.... Experiments of this class—those in which measurement of some kind is involved—are the proper work of a physical laboratory. In every experiment we have first to make our senses familiar with the phenomenon; but we must not stop here,—we must find out which of its features are capable of measurement, and what measurements are required in order to make a complete specification of the phenomenon. We must, then, make these measurements, and deduce from them the result which we require to find.
This characteristic of modern experiments—that they consist principally of measurements—is so prominent that the opinion seems to have got abroad that, in a few years, all the great physical constants will have been approximately estimated, and that the only occupation which will then be left to men of science will be to carry these measurements to another place of decimals.
If this is really the state of things to which we are approaching, our Laboratory may perhaps become celebrated as a place of conscientious labour and consummate skill; but it will be out of place in the University, and ought rather to be classed with the other great workshops of our country, where equal ability is directed to more useful ends.
But we have no right to think thus of the unsearchable riches of creation, or of the untried fertility of those fresh minds into which these riches will continually be poured.... The history of science shows that even during that phase of her progress in which she devotes herself to improving the accuracy of the numerical measurement of quantities with which she has long been familiar, she is preparing the materials for the subjugation of new regions, which would have remained unknown if she had been contented with the rough methods of her early pioneers.
The movement which was now to receive so great an impulse may be roughly dated from Sir William Thomsons first appearance as a Public Examiner in Cambridge; and Maxwell's own influence, as Examiner and Moderator, had been mainly instrumental in promoting it. The nature of the change has been described as follows by one whose University experience reaches back into the previous time:—
The style of mathematics which was popular in Cambridge for some time before was, to say the least, one-sided, and one-sided in a somewhat unproductive direction. There were many complaints that Cambridge was behind the rest of the scientific world, and that, whereas the students of so many other Universities were introduced to the splendid discoveries of such subjects as Electricity and Heat, the Wranglers of Cambridge spent their time upon mathematical trifles and problems, so-called, barren alike of practical results and scientific interest. Maxwell’s questions (as Moderator in 1866) infused fresh life into the Cambridge Tripos, and, therefore, into the University studies, by the number of original ideas and new lines of thought opened up by them, thus preparing for the change of system in 1873, when so many interesting subjects were added to the Examination.
Sir William Thomson gives the following important testimony to the same effect:—
The University, Glasgow,
21st January 1882.
The influence of Maxwell at Cambridge had undoubtedly a great effect in directing mathematical studies into more fruitful channels than those in which they had been running for many years. His published scientific papers and books, his action as an examiner at Cambridge, and his professorial lectures, all contributed to this effect; but above all, his work in planning and carrying out the arrangements of the Cavendish Laboratory. There is, indeed, nothing short of a revival of Physical Science at Cambridge within the last fifteen years, and this is largely due to Maxwell’s influence.
Evidence might easily be multiplied, but it is enough to quote the weighty words of Lord Rayleigh at a recent public meeting at Cambridge in support of the proposed Devonshire Memorial:—
It was no little thing to have had Professor Maxwell so closely connected with Cambridge, for by his genius effects were produced which could hardly have been produced in any other way. Before coming there to occupy the position he then held, he (Lord Rayleigh) had not given any particular attention to electricity, but he found Cambridge to be so saturated with the subject that he quickly came to the conclusion that it would be best to make it his particular study. All this was owing to the influence of Maxwell.[219]
While speaking of his work in lecturing, it may be well briefly to advert to the famous “Discourse on Molecules,” delivered before the British Association at Bradford in September 1873, which has been more often quoted than, perhaps, any other of his writings. This address was extremely rich in scientific matter, but its chief interest lay in the concluding paragraphs, which may be said to indicate more clearly than any other of Maxwell’s writings the position of his mind towards certain doctrines maintained by scientific men:—
In the heavens we discover by their light, and by their light alone, stars so distant from each other that no material thing can ever have passed from one to another; and yet this light, which is to us the sole evidence of the existence of these distant worlds, tells us also that each of them is built up of molecules of the same kinds as those which we find on earth. A molecule of hydrogen, for example, whether in Sirius or in Arcturus, executes its vibrations in precisely the same time.
Each molecule therefore throughout the universe bears impressed upon it the stamp of a metric system as distinctly as does the metre of the Archives at Paris, or the double royal cubit of the temple of Karnac.
No theory of evolution can be formed to account for the similarity of molecules, for evolution necessarily implies continuous change, and the molecule is incapable of growth or decay, of generation or destruction.
None of the processes of Nature, since the time when Nature began, have produced the slightest difference in the properties of any molecule. We are therefore unable to ascribe either the existence of the molecules or the identity of their properties to any of the causes which we call natural.
On the other hand, the exact equality of each molecule to all others of the same kind gives it, as Sir John Herschel has well said, the essential character of a manufactured article, and precludes the idea of its being eternal and self-existent.
Thus we have been led, along a strictly scientific path, very near to the point at which Science must stop,—not that Science is debarred from studying the internal mechanism of a molecule which she cannot take to pieces, any more than from investigating an organism which she cannot put together. But in tracing back the history of matter, Science is arrested when she assures herself, on the one hand, that the molecule has been made, and, on the other, that it has not been made by any of the processes we call natural.
Science is incompetent to reason upon the creation of matter itself out of nothing. We have reached the utmost limits of our thinking faculties when we have admitted that because matter cannot be eternal and self-existent it must have been created.
It is only when we contemplate, not matter in itself, but the form in which it actually exists, that our mind finds something on which it can lay hold.
That matter, as such, should have certain fundamental properties,—that it should exist in space and be capable of motion,—that its motion should be persistent, and so on,—are truths which may, for anything we know, be of the kind which metaphysicians call necessary. We may use our knowledge of such truths for purposes of deduction, but we have no data for speculating as to their origin.
But that there should be exactly so much matter and no more in every molecule of hydrogen is a fact of a very different order. We have here a particular distribution of matter—a collocation—to use the expression of Dr. Chalmers, of things which we have no difficulty in imagining to have been arranged otherwise.
The form and dimensions of the orbits of the planets, for instance, are not determined by any law of nature, but depend upon a particular collocation of matter. The same is the case with respect to the size of the earth, from which the standard of what is called the metrical system has been derived. But these astronomical and terrestrial magnitudes are far inferior in scientific importance to that most fundamental of all standards which forms the base of the molecular system. Natural causes, as we know, are at work, which tend to modify, if they do not at length destroy, all the arrangements and dimensions of the earth and the whole solar system. But though in the course of ages catastrophes have occurred and may yet occur in the heavens, though ancient systems may be dissolved and new systems evolved out of their ruins, the molecules out of which these systems are built—the foundation-stones of the material universe—remain unbroken and unworn. They continue this day as they were created—perfect in number and measure and weight; and from the ineffaceable characters impressed on them we may learn that those aspirations after accuracy in measurement, and justice in action, which we reckon among our noblest attributes as men, are ours because they are essential constituents of the image of Him who in the beginning created, not only the heaven and the earth, but the materials of which heaven and earth consist.
In 1875 he read before the Chemical Society a paper “On the Dynamical Evidence of the Molecular Constitution of Bodies.”
The lecture on Thermodynamics at the Loan Exhibition of Scientific Apparatus in London in 1876 (to which he had contributed his real-image Stereoscope, etc.), was illustrated by his own model of the Thermodynamic Surface.[220]
The last of his public lectures was the Rede Lecture “On the Telephone,” delivered at Cambridge in 1878, and illustrated with the aid of Mr. Gower’s Telephonic Harp.
After pointing out the extreme simplicity as well as the absolute novelty of the invention, he made it the text of a discourse which is remarkable both for suggestiveness and discursiveness.
I shall ... consider the telephone as a material symbol of the widely separated departments of human knowledge, the cultivation of which has led, by as many converging paths, to the invention of this instrument by Professor Graham Bell.
... In a University we are especially bound to recognise not only the unity of Science itself, but the communion of the workers of Science. We are too apt to suppose that we are congregated here merely to be within reach of certain appliances of study, such as museums and laboratories, libraries and lectures, so that each of us may study what he prefers. I suppose that when the bees crowd round the flowers it is for the sake of the honey that they do so, never thinking that it is the dust which they are carrying from flower to flower which is to render possible a more splendid array of flowers and a busier crowd of bees in the years to come.
We cannot therefore do better than improve the shining hour in helping forward the cross-fertilisation of the Sciences.
One great beauty of Professor Bell's invention is that the instruments at the two ends of the line are precisely alike.... The perfect symmetry of the whole apparatus—the wire in the middle, the two telephones at the ends of the wire, and the two gossips at the ends of the telephones, may be very fascinating to a mere mathematician, but it would not satisfy the evolutionist of the Spenserian type, who would consider anything with both ends alike, such as the Amphisbæna, or Mr. Bright’s terrier, or Mr. Bell’s telephone, to be an organism of a very low type, which must have its functions differentiated before any satisfactory integration can take place.
Accordingly many attempts have been made, by differentiating the function of the transmitter from that of the receiver, to overcome the principal limitation of the power of the telephone. As long as the human voice is the sole motive power of the apparatus, it is manifest that what is heard at one end must be fainter than what is spoken at the other. But if the vibration set up at one end is used no longer as the source of energy, but merely as a means of modulating the strength of a current supplied by a voltaic battery, then there will be no necessary limitation of the intensity of the resulting sound, so that what is whispered to the transmitter may be proclaimed ore rotundo by the receiver.
He then briefly referred to Edison's loud-speaking telephone, and went on to exhibit and explain the microphone of Professor Hughes.
I have said the telephone is an instance of the benefit to be derived from the cross-fertilisation of the sciences. ... Professor Graham Bell ... is the son of a very remarkable man, Alexander Melville Bell, author of a book called Visible Speech, and of other works relating to pronunciation. In fact his whole life has been employed in teaching people to speak. He brought the art to such perfection that, though a Scotchman, he taught himself in six months to speak English, and I regret extremely that when I had the opportunity in Edinburgh I did not take lessons from him.[221] Mr. Melville Bell has made a complete analysis and classification of all the sounds capable of being uttered by the human voice, from the Zulu clicks to coughing and sneezing; and he has embodied his results in a system of symbols, the elements of which are not taken from any existing alphabet, but are founded on the different configurations of the organs of speech.
... Helmholtz, by a series of daring strides, has effected a passage for himself over that untrodden wild between acoustics and music—that Serbonian bog where whole armies of scientific musicians and musical men of science have sunk without filling it up.
We may not be able even yet to plant our feet in his tracks and follow him right across—that would require the seven league boots of the German Colossus; but to help us in Cambridge we have the Board of Musical Studies vindicating for music its ancient place in a liberal education. On the physical side we have Lord Rayleigh laying our foundation deep and strong in his Theory of Sound. On the æsthetic 3side we have the University Musical Society doing the practical work, and, in the space between, those conferences of Mr. Sedley Taylor, where the wail of the Siren draws musician and mathematician together down into the depths of their sensational being, and where the gorgeous hues of the Phoneidoscope are seen to seethe and twine and coil like the
on the gates of that city, where
The special educational value of this combined study of music and acoustics is that more than almost any other study it involves a continual appeal to what we must observe for ourselves.
The facts are things which must be felt; they cannot be learned from any description of them.
All this has been said more than 200 years ago by one of our own prophets, William Harvey of Gonville and Caius College:—“For whosoever they be that read authors, and do not, by the aid of their own senses, abstract true representations of the things themselves (comprehended in the author’s expressions) they do not represent true ideas, but deceitful idols and phantasmas; by which means they frame to themselves certaine shadows and chimaeras, and all their theory and contemplation (which they call science) represents nothing but waking men’s dreams and sick men’s phrensies.”
After the opening of the Cavendish Laboratory in 1874, the most continuous, as well as the most important, work of the Chair was the superintendence of various courses of experiments, undertaken by young aspirants for scientific distinction. With characteristic loyalty and humility, Maxwell seems often to have taken more pride in their researches than in his own. To enumerate the men who were thus favoured would be to name many who are now amongst the most efficient teachers of science in the United Kingdom. But there can be nothing invidious in making particular mention of those who are named by Maxwell himself in his correspondence, although the omission of other names may be accidental. Besides Mr. W. Garnett, who was his demonstrator in the Laboratory from first to last, he refers with especial satisfaction to the work of Mr. George Chrystal, now Professor of Mathematics in Edinburgh, and to that of Mr. W. D. Niven.
Mr. Chrystal was encouraged by him to undertake a series of experiments for verifying Ohm’s Law respecting the relation between the current and the electro-motive force in a wire, on which some doubt had been thrown by Weber’s theories, and, in an opposite direction, by a series of experiments reported to the British Association by Dr. Schuster in 1874.
In consequence of these doubts a committee was appointed by the British Association consisting of Professor Maxwell, Professor Everitt, and Dr. Schuster, and the report of this committee was presented to the Association at their annual meeting in Glasgow in 1876. The report consists mainly of an account of two experimental investigations planned by Professor Maxwell and carried out in the Cavendish Laboratory by Mr. Chrystal. To this report Mr. Chrystal added a brief account of his experiments on the unilateral and bilateral deflection of a galvanometer, affording a possible explanation of Dr. Schuster’s result. The investigation proved that when a unit current passes through a conductor of a square centimetre section, its resistance does not differ from its value for indefinitely small currents by 0·000,000,001 per cent.
The scene of these congenial labours was surrounded with manifold associations, which his love for Cambridge intensified. He had pleasant intercourse with many persons there, and after a while resumed the habit of occasional essay writing. Under the name of Erănus (or picnic) a club of older men was formed, differing little apparently from the “Apostles,” except in the greater seriousness of the discussions. Dr. Lightfoot (now Bishop of Durham) and Professors Hort and Westcott were members of this little circle of congenial spirits. Maxwell’s contributions, containing his matured thoughts on various speculative questions, will be found in Chapter XIII. It may be remarked generally that the most marked feature of his later life was an ever-increasing soberness of spirit, and a deepening inward repose, which took nothing from the brightness of his companionship, but rather kept fresh the inexhaustible springs of cheerfulness and humorous mirth in him. The beginnings of such “life in earnest” may be traced far back, but are most obviously perceptible in his third year at Cambridge (1853),[222] in the summer of 1856, after his father’s death, and in the crisis of his life at Aberdeen (1857-8).
This graver tone by no means checked the playful impulses that burst forth from time to time in sparkling jeux d'esprits. It rather fledged his arrows, while it loaded them, giving them a steadier aim, so that his lightest effusions carried an unsuspected weight of meaning. His wit was never more brilliant, more incisive, or (it may be added) more perfectly good-humoured, than in the verses on Professor Cayley’s portrait, and the “Notes of the President’s Address.” He found time also to indulge his old taste for reading and writing in cypher, and thus, on one occasion, considerably disconcerted a contributor to the second column of the Times.
His outward appearance in these later years has been well described by one who saw him first in 1866:—
A man of middle height, with frame strongly knit, and a certain spring and elasticity in his gait; dressed for comfortable ease rather than elegance; a face expressive at once of sagacity and good humour, but overlaid with a deep shade of thoughtfulness; features boldly but pleasingly marked; eyes dark and glowing; hair and beard perfectly black, and forming a strong contrast to the pallor of his complexion.... He might have been taken, by a careless observer, for a country gentleman, or rather, to be more accurate, for a north country laird. A keener eye would have seen, however, that the man must be a student of some sort, and one of more than ordinary intelligence.
In later years his hair had turned to iron gray, but until a few years before his death he retained his elasticity of step.
The picture of Maxwell, as he appeared in 1866, became afterwards perfectly familiar to residents in Cambridge. They will remember his thoughtful face as he walked in the street, revolving some of the many problems that engaged him, Toby lagging behind, till his master would suddenly turn, as if starting from a reverie, and begin calling the dog.
The same authority continues—
... He had a strong sense of humour, and a keen relish for witty or jocose repartee, but rarely betrayed enjoyment by outright laughter. The outward sign and conspicuous manifestation of his enjoyment was a peculiar twinkle and brightness of the eyes. There was, indeed, nothing explosive in his mental composition, and as his mirth was never boisterous, so neither was he fretful or irascible. Of a serenely placid temper, genial and temperate in his enjoyments, and infinitely patient when others would have been vexed or annoyed, he at all times opposed a solid calm of nature to the vicissitudes of life.
In performing his private experiments at the laboratory, Maxwell was very neat-handed and expeditious. When working thus, or when thinking out a problem, he had a habit of whistling, not loudly, but in a half-subdued manner, no particular tune discernible, but a sort of running accompaniment to his inward thoughts.... He could carry the full strength of his mental faculties rapidly from one subject to another, and could pursue his studies under distractions which most students would find intolerable, such as a loud conversation in the room where he was at work. On these occasions he used, in a manner, to take his dog into his confidence, and would say softly, “Tobi, Tobi,” at intervals, and after thinking and working for a time, would at last say (for example), “It must be so: Plato (i.e. Plateau), thou reasonest well.” He would then join in the conversation.
... His acquaintance with the literature of his own country, and especially with English poetry, was remarkable alike for its extent, its exactness, and the wide range of his sympathies. His critical taste, founded as it was on his native sagacity, and a keen appreciation of literary beauty, was so true and discriminating that his judgment was, in such matters, quite as valuable as on mathematical writings. ... As he read with great rapidity, and had a retentive memory, his mind was stored with many a choice fragment which had caught his fancy. He was fond of reading aloud at home from his favourite authors, particularly from Shakspeare, and of repeating such passages as gave him the greatest pleasure.[223]
Maxwell wag rarely seen walking without a dog accompanying him, and, when visiting the Laboratory for a short time, Toby or Coonie, or both, would always attend him. Toby (II. or III.) came to Cambridge with Professor Maxwell in 1871, and was thoroughly conversant with the details of the Laboratory and some of its apparatus. He always betrayed signs of uneasiness when he heard electric sparks, but when summoned to his post he would sit down between his master’s feet and allow the electrophorus to be excited upon his back, growling all the time in a peculiar manner, as though to relieve his mind, but not evidencing any signs of real discomfort. On one occasion Toby sat quietly on an insulating support, and allowed himself to be rubbed with a cat’s skin, when it was found that the dog became positively electrified, contrary to the general belief that a cat’s skin is positive to everything; whereupon Professor Maxwell remarked that “a live dog is better than a dead lion.” It remains for a future physicist to determine the electric relations of a live cat and dog.
One great charm of Maxwell’s society was his readiness to converse on almost any topic with those whom he was accustomed to meet, although he always showed a certain degree of shyness when introduced to strangers. He would never tire of talking with boyish glee about the d——l on two sticks and similar topics, and no one ever conversed with him for five minutes without having some perfectly new ideas set before him; sometimes so startling as to utterly confound the listener, but always such as to well repay a thoughtful examination. Men have often asked, after listening to a conversation on some scientific question, whether Maxwell were in earnest or joking.[224] The charm of his conversation rendered it very difficult to carry on any independent work when he was present, but his suggestions for future work far more than compensated for the time thus spent.
On one occasion, after removing a large amount of calcareous deposit which had accumulated in a curiously oolitic form in a boiler, Maxwell sent it to the Professor of Geology with a request that he would identify the formation. This he did at once, vindicating his science from the aspersion which his brother professor would playfully have cast on it.
Maxwell still found occasional recreation in riding at Cambridge as well as more frequently at Glenlair, where he resided as much as he could consistently with his professional duties.[225] He always arranged to leave Cambridge at the end of the Easter term in time to officiate at the midsummer communion in the kirk at Parton, where he was an elder. His liberality in his own neighbourhood was very great. Besides the endowment of the church, and building of the manse at Corsock, he had planned a large contribution to the cause of primary education. When the School Board was instituted in the district, Maxwell was very anxious to keep up the school established in the reign of George III. at Merkland, in the immediate neighbourhood of the village of Kirkpatrick-Durham, in addition to the Board school at Corsock, five miles away. When this offer was refused, he set apart a site and had plans made for a school to be erected and supported at his own expense upon his estate, but failing health prevented the accomplishment of his purpose.
The last few years of Maxwell’s life were saddened by the serious and protracted illness of Mrs. Maxwell. Notwithstanding the inexhaustible freshness of his spirit, his work could not but be somewhat modified by a cause so grave. He was an excellent sick-nurse, and we have already seen how he attended upon Pomeroy when attacked with fever in college, how he devoted himself to his father during his illness, and how he cared for his brother-in-law when in London. On one occasion during Mrs. Maxwell’s illness he did not sleep in a bed for three weeks, but conducted his lectures and other work at the Laboratory as usual. While attending on his wife he would continue working at his manuscripts, or would arrange a series of experiments to be carried out by one of the workers at the Cavendish Laboratory; but the time which he could personally devote to his own experiments was very limited. The same cause prevented his attendance at meetings in London and at the British Association, for which, however, he retained his affection. His wonderful devotion to his wife, and the almost mystical manner in which he regarded the marriage tie, are sufficiently apparent from his letters.
The meeting of the British Association, held at Belfast in 1874 when Professor Tyndall was President, was the last which Maxwell attended. Before Section A he read a note “On the Application of Kirchhoff’s Rules for Electric Circuits to the Solution of a Geometrical Problem;” but his attendance at this meeting will be remembered chiefly on account of his paraphrase of the President’s address, which was published in Blackwood’s Magazine, and, together with the late Mr. Shilleto’s Greek translation of it, will be found reprinted in Part III. His verses on the Red Lions, a social club consisting of members of the Association, were also written at this meeting.
In university politics Maxwell was regarded as a Conservative, and, as such, in November 1876, he was elected a member of the Council of the Senate of the University. His views respecting various questions of university reform are sufficiently indicated by his letters, especially those addressed to Mr. Monro (see p. 269). He was also a member of the Mathematical Studies and Examinations Syndicate, which was appointed on 17th May 1877, and which sat every week during term for a whole year for the purpose of reorganising the Mathematical Tripos.
In 1873 and 1874 Professor Maxwell was one of the examiners for the Natural Sciences Tripos, and in 1873 he was the first “Additional Examiner” in the Mathematical Tripos under the new regulations which then came into force. This was the fifth time that he had examined in the Mathematical Tripos in the course of seven years. He was president of the Cambridge Philosophical Society during the session 1876-7.[226]
Besides many contributions to Nature and other similar publications during his residence in Cambridge, Maxwell wrote several articles for the Ninth Edition of the Encyclopœdia Britannica. The last scientific paper he ever wrote was the very brief article on Harmonic Analysis, the proof of which was sent for correction when its author was too weak to read it.
Although the publication of the Treatise on Heat and of the Electricity and Magnetism falls within this period, they were mainly written during the time of his retirement at Glenlair. The “small book on a great subject,” entitled Matter and Motion, was merely the concise expression of his most habitual thoughts. But his chief literary work during the last seven years of his life was the editing of the Electrical Researches of the Hon. Henry Cavendish, F.R.S.
Henry Cavendish was son of Lord Charles Cavendish and great uncle to the present Duke of Devonshire. He published only two papers relating to electricity—“An Attempt to Explain some of the Phenomena of Electricity by means of an Elastic Fluid” (Phil. Trans. 1771) and “An Account of some Attempts to Imitate the Effects of the Torpedo by Electricity” (Phil. Trans. 1776). He had prepared, however, some twenty packets of manuscript on Mathematical and Experimental Electricity. These, after his death, were placed by the then Earl of Burlington, now Duke of Devonshire, in the hands of the late Sir William Snow Harris, who appears to have made an abstract of them, with a commentary of great value on their contents. Of this abstract and commentary Professor Maxwell was unable to gain possession, but the Cavendish Manuscripts were placed in his hands by the Duke of Devonshire in 1874. The manner in which the contents of these manuscripts were investigated by Professor Maxwell, and the series of experiments he conducted in order to test Cavendish’s results, will be referred to in Part II. The final proof-sheets were returned to press during the summer of 1879, and the book was published in October of the same year. The letters on this subject, which will be found below, are types of very many that were written by Maxwell respecting the Cavendish papers.
The title of the book as published in October 1879 (one thick volume, 8vo) is An Account of the Electrical Researches of the Honourable Henry Cavendish, F.R.S., between 1771 and 1781. Few or none could have performed that task as he has performed it. And yet some may wish that these precious years had been given rather to the unimpeded prosecution of his own original researches.[227]
At my last meeting with him,—it was in his house at Cambridge, in the year 1877,—in the midst of some discursive talk, he took the MS. of this book out of a cabinet, and began showing it to me and discoursing about it in the old eager, playful, affectionate way, just as with the magic discs in boyhood, or the register of the colour-box observations at a later time, in the little study at Glenlair. “And what,” I said, “of your own investigations in various ways?” “I have to give up so many things,” he answered, with a sad look, which till then I had never seen in his eyes. Even before this, as it now appears, he had felt the first symptoms of the inexorable malady, which in the spring of 1879 assumed a dangerous aspect, and killed him in the autumn of that year.
Letters, 1871 to 1879—ÆT.. 39-48.