Popular Science Monthly/Volume 5/August 1874/Rendu and his Editors

by John Tyndall

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RENDU AND HIS EDITORS.

By JOHN TYNDALL.

"Some have blamed me, and some have praised me, for the part I have acted toward Rendu. In one distinguished, but not disinterested quarter, I am charged with prejudice and littleness of spirit, to which charge I make no reply. But let it be shown to me that I have wronged any man by false accusation, and Zaccheus was not more prompt than I shall be to make restitution."—("Mountaineering in 1861.")

TO review a book is an unusual occurrence with me: other duties putting in a prior and peremptory claim. Still I could not, when honored with a request to do so, decline making the few observations which the brief time allowed me renders possible, on a volume just published under the joint auspices of Prof. George Forbes, Prof. P. G. Tait, Prof. John Ruskin, and Mr. Alfred Wills.

Science and Art here unite in denouncing a small book of mine entitled the "Forms of Water," to which reference has been already made in these pages.^[1] Putting certain of its sentences into what they call "straightforward English," they draw the inference that my object in writing it was, in a more or less mean and underhand way, to "dim the lustre" of the late Principal Forbes's glacier-discoveries, to filch his laurels, and to dishonor his memory by fixing on him the charge of plagiarism." Other friends of the late Principal cannot, however, discover in the book any wickedness of this kind, while no friend of mine can discover it.

In the preface to the fourth edition of the "Forms of Water," published a few days ago, I state its origin, object, and spirit, and my attitude toward such criticisms as had then appeared, to be as follows: "I had been frequently invited to write on Glaciers in encyclopædias, journals, and magazines, but had always declined to do so. I had also abstained from making them the subject of a course of lectures at the Royal Institution, wishing to take no advantage of my position there, and indeed to avoid writing a line or uttering a sentence on the subject for which I could not be held personally responsible. In view of the discussions which the subject had provoked, I thought this the fairest course.

"But, in 1871, the time (I imagined) had come when, without risk of offense, I might tell our young people something about the labors of those who had unraveled for their instruction the various problems of the ice-world. My lamented friend and ever-helpful counselor, Dr. Bence Jones, thought the subject a good one, and accordingly it was chosen. Strong in my sympathy with youth, and remembering the damage done by defective exposition to my own young mind, I sought, to the best of my ability, to confer upon these lectures clearness, thoroughness, and life.

"I aimed, indeed, at nothing less than presenting to my youthful audience, in a concentrated but perfectly digestible form, every essential point embraced in the literature of the glaciers, and some things in addition, which, derived as they were from my own recent researches, no book previously published on this subject contained. But my theory of education agrees with that of Emerson, according to which instruction is only half the battle: what he calls provocation being the other half By this he means that power of the teacher, through the force of his character and the vitality of his thought, to bring out all the latent strength of his pupil, and to invest with interest even the driest matters of detail. In the present instance, I was determined to shirk nothing essential, however dry; and, to keep my mind alive to the requirements of my pupil, I proposed a series of ideal ramblings, in which he should be always at my side. Oddly enough, though I was here dealing with what might be called the abstract idea of a boy, I realized his presence so fully as to entertain for him, before our excursions ended, an affection consciously warm and real.

"A German critic, whom I have no reason to regard as specially favorable to me or it, makes the following remark on the style of the book: 'This passion' (for the mountains) 'tempts him frequently to reveal more of his Alpine wanderings than is necessary for his demonstrations. The reader, however, will not find this a disagreeable interruption of the course of thought; for the book thereby gains wonderfully in vividness.' This, I would say, was the express aim of the breaks referred to. I desire to keep my companion fresh as well as instructed, and these interruptions were so many breathing-places where the intellectual tension was purposely relaxed and the mind of the pupil braced to fresh action.

"Of other criticisms, flattering and otherwise, I forbear to speak. As regards some of them, indeed, it would be a reproach to that manliness which I have sought to encourage in my pupil to return blow for blow. If the reader be acquainted with them, this will let him know how I regard them; and if he be not acquainted with them, I would recommend him to ignore them, and to form his own judgment of this book. No fair-minded person who reads it will dream that I, in writing it, had a thought of acting otherwise than justly and generously toward my predecessors, the last of whom,^[2] to the grief of all who knew him, has recently passed away." I thus show how willing I was three weeks ago to let discussion cease.

How a great and good man regarded this book is shown by the following extract from a letter from the late Prof. Sedgwick, to whom I sent the first draft of the volume. I gather from the "Life and Letters" that he was a friend of Principal Forbes. The extraordinary freshness of his nature breaks through the concluding lines, which, save as an illustration of this, I should hardly have ventured to quote. There are others which I omit for obvious reasons:

"Cambridge, January 29, 1878.

"My dear Professor: I write to thank you for the little book upon the glaciers of the Alps you had the kindness to send to me, and for the instruction and delight its perusal gave me.... It shows a power of putting the subject in the clear, bright colors of daylight before the reader's eyes, and making him feel as if he were your happy companion and fellow-laborer.

"Truly and gratefully yours,A. Sedgwick."

This is the language of a philosopher who took my words as they stand, and did not think it necessary "to put that and that together," so as to convert my statements into "straightforward English."

The law of causality is now an a priori dictum of the human mind. There is no spontaneous generation of phenomena; and, like all other things, the book now under consideration had its antecedents. These are in great part to be found in a discussion which occurred twelve years ago regarding the scientific position of a noble but a suffering man. By his unaided genius, Dr. Robert Julius Mayer, of Heilbronn in Germany, reached the heart of a generalization, which the professional hierarchy of science in his day had failed to reach, and which in its later developments ranks as high as the principle of gravitation. For this great Bahnbrecher I sought recognition; but the recognition was by no means immediate, nor was my act applauded by all. Much the reverse. I was accused, not only of want of patriotism, but of "depreciation and suppression." I was charged with ignorance, and an "abuse of language." Every spark of originality was denied to Dr. Mayer. The calculation of the mechanical equivalent of heat, which I had ascribed to him, was claimed for M. Seguin, who, it was alleged, had, three years before Mayer, made the same calculation, and obtained the same numerical result. These assertions were uttered with a confidence not surpassed by any thing contained in the volume just published by Mr. Macmillan, The sufficient reply to all this now is, that, since those days of strife, Dr. Mayer has received the highest rewards which the greatest scientific academies and societies in Europe could confer upon him; and that he now stands above detraction and debate, immovably fixed beside his illustrious experimental brother, Joule: a figure memorable to all time in the annals of science.

The gentle knight who in those days, with such conspicuous disaster to himself, took the field against me, is also my chief opponent now. He is the principal figure among the authors to whom I have referred, and I allude to these facts in order to bring him and his work into the causal series of contemporary phenomena, and to show cause for the warning that obstinacy of assertion on his part furnishes a by no means sufficient assurance that his assertions are objectively correct. Indeed, where we find these assertions associated with more than the usual want of sweetness and luminosity, the presumption arises that the judgment which proved entirely fallacious on a former occasion may at present, to say the least of it, be unsound.

The volume which calls forth these remarks is entitled "Theory of the Glaciers of Savoy," by M. le Chanoine Rendu; and the middle of the book is, I am happy to say, occupied by a translation of this remarkable essay—in itself a perfectly honorable and praiseworthy work. The volume opens with an introduction by Prof. George Forbes, son of the late Principal Forbes, which, measured by former discussions on this subject, is by no means immoderate in tone. Had this tone, indeed, been preserved throughout the discussion, these remarks of mine would never have been written. It is not in my nature to refuse sympathy to a son battling, as he imagines, for the honor of his father. But Prof. George Forbes has deliberately taken upon himself the responsibility of writings, samples of which shall be given further on, not with the view of maintaining his father's honor, but with the view of gratuitously sullying the honor of others. This, filial allegiance neither demands nor can excuse.

He prints some letters in his Introduction animadverting more or less upon me and my friends; but written at a time when the writers were very inperfectly acquainted with the subject on which they wrote. Dr. Whewell was from the first a warm supporter of Principal Forbes, and an equally warm opponent of Mr. William Hopkins; and, when my small labors on the glaciers came to be discussed, the preëxisting difference between these two distinguished men became intensified, in a high degree. It was Dr. Whewell who, in discussion with Mr. Hopkins, summed up my doings with the remark that I had simply taken Auguste Balmat to the summit of Mont Blanc and caused him to be frost-bitten.^[3] It was he who in 1859 proposed Principal Forbes as a candidate for the Copley medal,^[4] which the Council of the Royal Society did not grant. He was angry at the time; but it pleases me to remember that subsequently in the Athenæum Club he renewed acquaintance with me, and gave me the benefit of his most agreeable and instructive conversation about glaciers.

The letter from Dr. Playfair can also be placed in a moment in its proper relation to other facts. A foot-note at page 195 of the first edition of "Heat as a Mode of Motion" runs thus: "Since the above was written, the 'Glaciers of the Alps' has been published, and soon after its appearance a 'Reply' to those portions of the work which referred to Rendu was extensively circulated by Principal Forbes. For more than two years I have abstained from answering my distinguished censor, not from inability to do so, but because I thought, and think, that within the limits of the case it is better to submit to misconception than to make science the arena of a purely personal controversy." Not for two years, but for ten years did I permit, for peace' sake, this misconception to continue; it refers to allegations as to omissions made against me by Principal Forbes, and disposed of at p. 498 et seq., vol. xxii. of the Contemporary Review.

It will be seen at the place here referred to, that the strongest argument of Principal Forbes relates to a statement regarding crevasses made by Rendu; and Mr. George Forbes now contends for the correctness of his father's views. I can assure him, in all good temper and good faith, that he is hopelessly wrong; that his father entirely misapprehended Rendu; and that the argument founded on this misapprehension, though apparently so incontrovertible, and so damaging to me, is in reality not worth the paper on which it stands. During the lifetime of Principal Forbes I never once disturbed him in the enjoyment of his delusive triumph, and my life also would have passed without any attempt at refutation had not his biographers flaunted the argument again in my face, and compelled me to reduce it to the condition in which it appears in my last article. Had I, as alleged, been disposed to wound Principal Forbes, I should not have acted thus.

I had stated in the "Glaciers of the Alps," and in this Review, that some very important measurements made by Agassiz in 1841 and 1842, by which the differential motion of a glacier was demonstrated, had been ignored in all the writings of Principal Forbes. Though so much occupied with the subject, I was in absolute ignorance of the existence of these measures myself until my attention was drawn to them by Sir Charles Wheatstone, immediately before the publication of the "Glaciers of the Alps." Prof. George Forbes now charges me with forgetfulness of the fact that it was his father who suggested to M. Agassiz the measurements he made; meaning thereby, I suppose, to intimate that his father was not called upon to recognize measurements which were the result of his own instruction. I would, however, ask Mr. Forbes to consider whether I, while endeavoring to hold the balance fairly between contending claims, should have been justified in accepting his father's assertion and ignoring the diametrically opposite assertion of Agassiz? On this point I would direct his attention to two sources of information; the one probably known to him, the other unknown, and which the desire not to inflame this controversy has prevented me from publishing hitherto.

In the first place, I will make a brief extract from a very rare brochure published by Agassiz, in evident affliction of mind, in 1842. In that pamphlet he addresses thus his guest of the previous autumn:

"What eloquence have I not wasted in order to cause you to accept such and such a conclusion; what lengthened excursions, extending over days, have I not made to convince you of such and such a fact? And what advantage did I derive from nearly a month of these labors? This solely. On every new subject of discussion you favored me with the profound reflections: it is very curious; it is very extraordinary; it is most remarkable; it is capable of various interpretations; various causes might have produced these effects! Never a word on the true basis of the question. And, notwithstanding this, I told you all, showed you all, even things regarding which I had published nothing."

I was in duty bound to give due weight to this side of the question; and in 1869, prior to the publication of the "Glaciers of the Alps," I wrote to M. Agassiz, inquiring whether he still maintained the position here assumed; which, it will be seen, not only touches, but is, the very point brought forward by Prof. George Forbes. I will give the pith of his reply, which, as just intimated, has lain beside me unpublished for fifteen years. After sketching the "incredible difficulties" of his early glacier campaigns, his uncertainty regarding the measurement of the motion of bowlders, his failure on the Aar, and Escher's failure on the Aletsch, to determine the motion of a series of stakes fixed in 1840, because, through ignorance of the amount of ablation, they did not sink them deep enough in the ice, Agassiz answers me thus:

"It was not until after my second visit to the Aar in the winter of 1840–'41 that I felt myself prepared for a systematic experimental investigation of the glacier; and I then went up, not with the hope of solving all the problems in one year, but with the view of laying the basis of a solution. The fact that I staked a series of poles across the whole width of the glacier, to a depth which left them standing to the following year, and that I then went up with an experienced engineer to make a minute map of the entire surface of the glacier, which was executed, will show that I had laid my plans for a successful survey of glacier phenomena before Prof. Forbes had, for the first time, set his foot upon the glaciers with a view to studying them.

"When I invited him to spend some time with me upon the glacier in 1841, I hoped to receive some valuable hints for my investigations from a physicist of so high a standing as his. But he never suggested any thing to me, while I showed him every thing I had been doing, explained all my difficulties, and the

devices with which I proposed to overcome them. That Prof. Forbes reached the Mer de Glace in 1842, a few weeks before I went up the Glacier of the Aar, only gave him the opportunity of making a few days' observations at a time when I had already gained an annual average. That Prof. Forbes knew in 1841 of my intention to make this experiment I can affirm the more positively as he saw the iron bars with which I intended to bore the holes, and which had been carried up the glacier before he reached the Grimsel. That I was going to use instruments of precision in these measurements he must have understood, since I repeatedly mentioned my purpose of making a trigonometrical survey of the glacier the following year. Whether I at any time mentioned the theodolite I cannot remember now. But I am sure that he never suggested any thing to me.

"Allow me one more remark. Everybody knows that I am a naturalist, and not a physicist. My interest in the glaciers arose from a desire to learn something of the mammoth of Siberia, after I had become convinced by Charpentier that the glaciers of Switzerland were much more extensive in earlier times than now. It struck me that there might be some connection between the burial of these gigantic mammalia in the arctic regions and the wider range of glaciers in Switzerland; I am one of those who believe, as you expressed it in your short and characteristic speech at Geneva, that 'Nature is One,' and so I was led to study the accumulations of ice without the necessary preparation. This you cannot fail to perceive in reading the accounts of my successive attempts, and for this, I hope, some allowance will hereafter be made."

This account fairly tallies with the statement of Prof. Forbes in his "Travels," quoted in his "Life" (p. 503):

"Far from being ready to admit, as my sanguine companions wished me to do in 1841, that the theory of glaciers was complete, and the cause of their motion certain, after patiently hearing all that they had to say, and reserving my opinion, I drew the conclusion that no theory which I had then heard of could account for the few facts admitted on all hands, and that the very structure and motions of glaciers remained still to be deduced from observation."

Incomparably greater than Forbes in his own field, the want of physical knowledge, to which Agassiz refers at the conclusion of the foregoing letter, rendered him, on this particular ground, a mere child in comparison with his guest. Still, if the statement which I have italicised in Agassiz's letter express a fact, then, while entertaining no doubt that Prof. Forbes justified his conduct to his own mind, I leave it to others to judge whether it would not be an evil day for the frankness of scientific intercourse if such conduct should become general.

It is difficult at the present day and hour to convey an idea of the stir caused by the communication of our joint paper to the Royal Society by Mr. Huxley and myself; but many of us remember the violent discharge of letters which followed that event. Had I in those days a tendency to be puffed up, the circumstances were certainly such as might exalt my self-importance. But, as a matter of fact, the whole business was exceedingly saddening to me. For two years I endeavored, while not flinching from what I held to be the duty of a scientific man, to turn away by soft answers the wrath excited against me. I failed to do so. The tone of depreciation indulged in was typified by the remark of Dr. Whewell above quoted, and threats of punishment were everywhere rumored. I refer to these almost forgotten occurrences, which need never have been revived, to show how natural it would have been for me to assume in the "Glaciers of the Alps" a more decidedly controversial tone than that actually assumed in it.

Many of the claims then made for Principal Forbes were perfectly inconsistent with the facts known to me. Sir Charles Wheatstone had pointed out those measurements to which Agassiz refers as having been begun under Prof. Forbes's eyes, and which were more than ignored. I had also read Rendu's Essay, and found there matters absolutely unknown to the supporters of Principal Forbes, and directly at variance with statements current in high quarters. I also noticed, or thought I noticed, a tendency, glanced at in my former article, to regard the self-same data as important or unimportant according as they were employed by Forbes or Rendu.

Let me illustrate my meaning here. One of the strongest passages cited by Principal Forbes to show that he had recognized the merits of Rendu, which I never denied, but expressly admitted, is this ("Travels," page 382): "The idea of comparing a glacier to a river is any thing but new, and I would not be supposed to claim that comparison or analogy as an original one. Something very like a conception of fluid motion seems to have been in the minds of several writers, although I was not aware of it at the time that I made my theory. In particular, M. Rendu, whose mechanical views are in many respects more precise than those of his predecessors or contemporaries, speaks of 'glaciers d'Écoulement' as distinct from 'glaciers Reservoirs,' and in the quotation at the head of this chapter he contemplates the possibility of the mutual pressures of the parts overcoming the rigidity. He is the only writer of the glacier school who has insisted on the plasticity of the ice, shown by moulding itself to the endlessly varying form and section of its bed; and he is also opposed to his leading contemporaries in his conjecture that the centre of the ice-stream would be found to move fastest. But," and here comes one of those qualifying phrases to which I have already referred,^[5]—"M. Rendu has the candor not to treat his ingenious speculations as leading to any certain result, not being founded on experiments worthy of confidence."

I will ask permission to go one step farther. At the British Association Meeting at York, that able mathematician and high-minded gentleman, Mr. W. Hopkins, got into a sharp discussion with Prof. Forbes regarding the viscous theory, and he, subsequently, wrote upon the subject in the Philosophical Magazine. In the same journal Forbes published a reply; one of the strongest points of which, if not the very strongest point, is the following. Speaking of the principle of plasticity, Prof. Forbes writes:

"Perhaps the following illustration will appear to the impartial reader almost a demonstration of this principle.… There is a glacier basin in the range of Mont Blanc called the Glacier du Talèfre. Its outline is correctly represented in the next figure, as well as the relative dimensions of the mouth or outlet by which it pours forth the mass of ice which it is annually unable to contain in its circuit. The breadth of the outlet is about seven hundred yards, while the greater diameter of the basin which it discharges is more than forty-two hundred yards, or at least six times greater. Can it for one moment be imagined that any degree of lubrication of the bed of this cake of ice could drag it through the strait in question, even if its adhesion to the soil were absolutely nothing? The thing is impossible; it speaks for itself."^[6]

The observation here referred to as so convincing is precisely of that class upon which Rendu founded his theory; and there cannot be a reasonable doubt that the very fact here brought forward more or less influenced him. Still, while in the hands of Prof. Forbes it has the value here set forth, in those of Rendu the "ingenious speculations" founded upon it are not "worthy of confidence."

It is not, and never was, my design to charge Principal Forbes with conscious wrong; but, at the time here referred to, I believed him to be animated by a love of public recognition so eager, and an estimate of the value of his own work so exalted, as to render it difficult for him to behave in a generous way toward those whose labors trenched upon his own. I regarded his treatment of Agassiz as harsh, if not merciless. Considering all this, I do not think that the "Glaciers of the Alps," written in the midst of such contentions as I have indicated, can be justly deemed intemperate in tone. Its logic is sometimes stern;^[7] but its statements are irrefutable. To its chapters, from page 269 onward, I would refer the reader for an answer to a good deal of the irrelevant bluster associated with this question.

I am blamed for saying that, if Rendu had added to his other qualifications those of a land-surveyor, he would now be deemed the "Prince of Glacialists." Can this be for a moment doubted? When we find him announcing, with a fullness and precision never surpassed, and not attained even by Prof. Forbes himself until years after the publication of his "Travels," the character of glacier-motion; when we find him laboriously trying to determine it by observations of blocks at the edge and toward the middle of the glacier—is it to be imagined that, if he knew the use of the theodolite, he would not have employed that instrument? And is the absence of this surveyor's knowledge a just reason for dismissing his labors in the following fashion in the "Life and Letters of Principal Forbes?" After having referred to the Dilatation and Gravitation Theories, and to an observation of Playfair's, the writer proceeds: "We are not aware that any thing of particular importance beyond this was known, in the sense of having been observed, not merely seen, till Forbes took up the subject, with the exception of Rendu's acute remark, which appears to have been previously made by Captain Basil Hall and others, that a glacier seems to flow in its channel like a sluggish stream." This is as inadequate as it is unjust; and I would also, once for all, respectfully protest against the following language as describing with even approximate fairness the relation of Rendu to this question: "One of the few men who seems in any point of consequence to have had even one clear and accurate idea on the subject before Forbes is Mgr. Rendu, late Bishop of Annécy, but this was so mixed up with error that it does not appear likely that in his hands it could have ever led to any thing definite; for Rendu holds and enunciates, sometimes in the same sentence, facts and errors utterly incompatible with them."^[8] This is the spirit of depreciation which has introduced bitterness into these discussions, and which will not be shared by any just or generous mind.

Prof. Tait has prepared himself for his portion of the book here under review by some researches which prove that a "grudge on my part against Prof. Forbes was in full bud as early as 1854." He moreover credits me with "extremely great skill in choosing precisely such forms of language as were calculated to produce the most exquisite torture in the mind of a scrupulously upright and high-souled man." That I should exhibit skill in any thing is to me astonishing. What he here says, coupled with what he had said before regarding my ignorance, is a mere feeble copy of his description of Mr. Lowe—a man "compounded in about equal proportions of fiend and fool;" and such repetition is unworthy of the versatile genius of Prof. Tait. Speaking seriously, we have, in both cases, the mere wildness of uncontrolled anger. I had no more grudge against Prof. Forbes in 1854 than against Prof. Faraday, and friendly letters passed between Forbes and myself long subsequent to this date. In fact, if I had any grudge, it was rather against Agassiz than against Forbes, for in those days I was impatient with Agassiz's physics, but otherwise ill acquainted with the merits of the case between them. Might I commend to my critic the following deliverance of his distinguished countryman Prof. Bain? "Our emotions of anger, like fear, are manifestations superinduced upon mere pain. Revenge, antipathy, hatred, party spirit, are so many forms of the irascible feeling, and are antagonistic in a conspicuous degree to the ascertaining of truth. Calumny, the expression of anger, connotes falsehood."

I willingly accept Prof. Tait's grammatical correction as regards the introduction of two articles, and the substitution of the word "mutual" for "natural" in the statement of the viscous theory. Such mistakes readily escape me in the reading of proofs with the meaning of which I am very familiar; and some similar errors in my other works, discovered mainly by my own pupils, await correction in subsequent editions. In the "Glaciers of the Alps," my critic will find "mutual" all right, and one of the indefinite articles supplied. But the shifting of the vowel to a consonant was overlooked, and the second article was therefore omitted.

From the level of the irascible. Prof. Tait on one occasion rises to that of exultation. "While we write," he exclaims, "another actor has appeared on the scene—and with tremendous effect. The terrible words of Mr. Ruskin (Fors Clavigera, Letter xxxiv.), with regard to Dr. Tyndall and his 'Forms of Water,' will reach myriads of intelligent readers besides those who could otherwise be expected to interest themselves in a question involving scientific issues. Mr. Ruskin's admirable command of language, his clearness, impartiality, acuteness, and his exemplary firmness in declaring truth, and doing justice, leave nothing to be desired."

These are strong words. What is their value? Let a very able sample of Mr. Tait's countrymen reply. "He" (Prof. Tait), says the Scotsman of April 24th, "may be occasionally shy in his substantives, but he has no timidity in his adjectives. 'Contemptible,' 'unutterably contemptible,' 'miserable,' 'disgusting,' 'shabby,' 'pernicious,' 'pestilent,' 'hideous,' are among the projectiles, more natural perhaps than philosophical, which the Professor of Natural Philosophy distributes round him." But whence, it may be asked, this exorbitant jubilation? What on earth can the opinion of Mr. Ruskin have to do with the solution of a question which has stood in the fierce light of scientific discussion for fourteen years? Is it to be imagined that he has found something which has escaped Helmholtz or Sedgwick? Surely, if Prof. Tait will only give his clouds of anger time to disappear, he will see the absurdity of introducing such loose rhetoric among grave students of science.

Further on we have Principal Forbes's pure and disinterested love of knowledge for its own sake, contrasted with that of others who seek it for the sake of notoriety. Let me examine this notion in the light of a crucial instance.

In walking up the glacier of the Aar with Agassiz, Prof. Forbes observed blue veins running through the ice. Agassiz had noticed the grooves answering to them on the surface, but he had not studied them, and in all likelihood he blundered in his conversation about them with his acute and physically-cultured guest. They followed these veins subsequently together for several days, and, after the departure of Forbes, Agassiz traced them to a depth of a hundred and twenty feet. Humboldt, I am informed, had been instrumental in getting him pecuniary aid for his researches, and to Humboldt, after the glacier campaign of 1841 had ended, he addressed a private note, mentioning among other things his having seen the veins. I make no attempt at excusing his omission of the name of Forbes from this note; but, taking every thing into account, the sin of omission does not seem very heinous. Its effect upon Prof. Forbes shall be described by himself.

"I reached home," he says, "in the month of October, 1841, and soon commenced the historical review of the glacier question which I had projected. While I was thus engaged, the 'Comptes Rendus' of the Academy of Sciences in Paris for the 18th of October reached me. In it I found a letter from M. Agassiz to Baron Humboldt, containing the following passage with reference to the observations made upon the glacier of the Aar:

"'Le fait le plus nouveau que j'ai remarqué, c'est la présence dans la masse de la glace des rubans verticaux de glace bleue, alternant avec des bands de glace blanche d'un quart de ligne à plusieurs pouces de large, s'étendant sur toute la longueur du glacier et penetrant à une profondeur du moins 120 pieds puisque j'ai observé encore ce phénomène an fond du trou de sonde.'

"On reading this letter," says Principal Forbes, "from which even all mention of my presence on the Aar is excluded, my first impression was of surprise and pain. That I could not suffer so direct a plagiarism to remain unchallenged never appeared to me to admit of a doubt; le fait le plus nouveau que j'ai remarqué was an assertion as articulate as it was unfounded."

For nearly a month Prof. Forbes had shared the shelter of Agassiz's roof, and wandered with him among scenes of unsurpassed grandeur. He had found in his host "noble ardor, generous friendship, unvarying good temper, and true hospitality." It is upon the man thus described by himself that Prof. Forbes turns in this fierce way, for the mere omission of his name. It grieves me to say a word which could be interpreted as severe to a dead man; but the comparisons drawn by his panegyrist compel me to state that, among the eminent men whom it is my privilege to call my friends, there is not one to whom such an explosion of resentment for so purely personal—I had almost said paltry—a cause would be even approximately possible. I charge him with nothing consciously unfair; but from a man so hot in the assertion of his "claims," so sensitive to public recognition, and so free in the use of hard words, these interminable discussions run as naturally as rivers from their water-shed.

With more time at my disposal I should probably enter more fully into these matters; but this and my former article, taken in conjunction with the "Forms of Water," in which, even to the ignoring of myself, I desire to do justice both to Agassiz and Forbes, and the pages referred to in the "Glaciers of the Alps," will have so far cleared a dusty atmosphere as to enable any really earnest reader to see the bearings of this question. It now only rests with me to give some samples of those "terrible" and "tremendous" words to which Prof. Tait has referred, and which Prof. George Forbes has thought fit to make a portion of his volume. Forty years ago, Mr. Ruskin first saw the Alps from Schaffhausen.

"Only one great step," he says, "in the knowledge of glaciers has been made in all that period; and it seems the principal object of Prof. Tyndall's book to conceal its having been taken, that he and his friends may get the credit, some day, of having taken it themselves.... At the end of the last book of his he" (Prof. Tyndall) "denies, as far as he dares, the essential points of Forbes's discovery.... The readers of 'Fors' may imagine they have nothing to do with personal questions of this kind, but they have no conception of the degree in which general science is corrupted and retarded by those jealousies of the schools; nor how important it is to the cause of all true education that the criminal indulgence of them should be chastised. Criminal is a strong word, but an entirely just one. I am not likely to overrate the abilities of Prof. Tyndall; but he had at least intelligence enough to know that his dispute of the statements of Forbes by quibbling on the word viscous was as uncandid as it was unscholarly; and it retarded the advance of glacier science for at least ten years.... And the absurdity, as well as the iniquity, of the professor's willful avoidance of this gist of the whole debate is consummated in this last book, in which, though its title is the 'Forms of Water,' he actually never traces the transformation of snow into glacier-ice at all."

If these "terrible" words be true words, why was it left to an amateur to utter them? Why were they not uttered years ago by Prof. Tait himself? To these and other observations of Mr. Ruskin I offer no reply; nor should I have ever given them the slightest regard or attention were it not for the use which a scientific man has stooped to make of them.

"Fors Clavigera" has but a scanty circulation—how, then, were the "myriad intelligent readers" of Prof. Tait obtained? Simply by circulating "Fors" in Scotland, and republishing Mr. Ruskin's article in the Scotch newspapers. Prof. Tait, moreover, was for some years attached to Queen's College, Belfast, and I am to have the honor of presiding at the meeting of the British Association to be held next August in that city. Accordingly, the article in "Fors" has been republished in the Belfast journals also. The Northern Whig and the Belfast Newsletter have duly reached me with Mr. Ruskin's article conspicuously marked. These are some of the amenities of Prof. Tait: others are at hand, but I refuse to notice them. The spirit which prompts them may, after all, be but a local distortion of that noble force of heart which answered the "Cameron's gathering" at Waterloo; carried the Black Watch to Coomassie; and which has furnished Scotland with the materials of an immortal history. Still, rudeness is not independence, bluster is not strength, nor is coarseness courage. We have won the human understanding from the barbarism of the past; but we have won along with it the dignity, courtesy, and truth of civilized life. And the man who on the platform or in the press does violence to this ethical side of human nature discharges but an imperfect duty to the public, whatever the qualities of his understanding may be.—Contemporary Review.

1. Vol. xxii., p. 484.
2. Agassiz.
3. Contemporary Review, vol. xxii., p. 485.
4. On this subject, see Prof. Huxley's masterly letter in Nature, May 22, 1873.
5. Contemporary Review, vol. xxii., p. 507.
6. Philosophical Magazine, vol. xxvi., pp. 414, 415.
7. What a courteous demeanor might have done to modify this, I cannot now say, but I know that, after the death of Principal Forbes, no reference of mine to his work or memory lacked appreciation or kindness.
8. Prof. Tait in "Life and Letters of Forbes," pp. 494, 498.