I.

GEOLOGICAL.

[From “The Reader,” November 12, 1864.]

_THE CONFORMATION OF THE ALPS._

DENMARK HILL, 10_th November_, 1864.

My attention has but now been directed to the letters in your October numbers on the subject of the forms of the Alps.[160] I have, perhaps, some claim to be heard on this question, having spent, out of a somewhat busy life, eleven summers and two winters (the winter work being especially useful, owing to the definition of inaccessible ledges of strata by new-fallen snow) in researches among the Alps, directed solely to the questions of their external form and its mechanical causes; while I left to other geologists the more disputable and difficult problems of relative ages of beds.

I say “more disputable” because, however complex the phases of mechanical action, its general nature admits, among the Alps, of no question. The forms of the Alps are quite _visibly_ owing to the action (how gradual or prolonged cannot yet be determined) of elevatory, contractile, and expansive forces, followed by that of currents of water at various temperatures, and of prolonged disintegration--ice having had small share in modifying even the higher ridges, and none in causing or forming the valleys.

The reason of the extreme difficulty in tracing the combination of these several operative causes in any given instance, is that the effective and destructive drainage by no means follows the leading fissures, but tells fearfully on the softer rocks, sweeping away inconceivable volumes of these, while fissures or faults in the harder rocks of quite primal structural importance may be little deepened or widened, often even unindicated, by subsequent aqueous action. I have, however, described at some length the commonest structural and sculptural phenomena in the fourth volume of “Modern Painters,” and I gave a general sketch of the subject last year in my lecture[161] at the Royal Institution (fully reported in the _Journal de Genève_ of 2d September, 1863), but I have not yet thrown together the mass of material in my possession, because our leading chemists are only now on the point of obtaining some data for the analysis of the most important of all forces--that of the consolidation and crystallization of the metamorphic rocks, causing them to alter their bulk and exercise irresistible and irregular pressures on neighboring or incumbent beds.

But, even on existing data, the idea of the excavation of valleys by ice has become one of quite ludicrous untenableness. At this moment, the principal glacier in Chamouni pours itself down a slope of twenty degrees or more over a rock two thousand feet in vertical height; and just at the bottom of this ice-cataract, where a water-cataract of equal power would have excavated an almost fathomless pool, the ice simply accumulates a heap of stones, on the top of which it rests.

The lakes of any hill country lie in what are the isolated lowest (as its summits are the isolated highest) portions of its broken surface, and ice no more engraves the one than it builds the other. But how these hollows were indeed first dug, we know as yet no more than how the Atlantic was dug; and the hasty expression by geologists of their fancies in such matters cannot be too much deprecated, because it deprives their science of the respect really due to it in the minds of a large portion of the public, who know, and _can_ know, nothing of its established principles, while they can easily detect its speculative vanity. There is plenty of work for us all to do, without losing time in speculation; and when we have got good sections across the entire chain of the Alps, at intervals of twenty miles apart, from Nice to Innspruch, and exhaustive maps and sections of the lake-basins of Lucerne, Annecy, Como, and Garda, we shall have won the leisure, and may assume the right, to try our wits on the formative question.

J. RUSKIN.[162]

[From “The Reader,” November 26, 1864.]

_CONCERNING GLACIERS._

DENMARK HILL, _November_ 21.

I am obliged to your Scottish correspondent for the courtesy with which he expresses himself towards me; and, as his letter refers to several points still (to my no little surprise) in dispute among geologists, you will perhaps allow me to occupy, in reply, somewhat more of your valuable space than I had intended to ask for.

I say “to my no little surprise,” because the great principles of glacial action have been so clearly stated by their discoverer, Forbes, and its minor phenomena (though in an envious temper, which, by its bitterness, as a pillar of salt, has become the sorrowful monument of the discovery it denies)[163] so carefully described by Agassiz, that I never thought there would be occasion for much talk on the subject henceforward. As much as seems now necessary to be said I will say as briefly as I can.

What a river carries fast at the bottom of it, a glacier carries slowly at the top of it. This is the main distinction between their agencies. A piece of rock which, falling into a strong torrent, would be perhaps swept down half a mile in twenty minutes, delivering blows on the rocks at the bottom audible like distant heavy cannon,[164] and at last dashed into fragments, which in a little while will be rounded pebbles (having done enough damage to everything it has touched in its course)--this same rock, I say, falling on a glacier, lies on the top of it, and is thereon carried down, if at fullest speed, at the rate of three yards in a week, doing usually damage to nothing at all. That is the primal difference between the work of water and ice; these further differences, however, follow from this first one.

Though a glacier never rolls its moraine into pebbles, as a torrent does its shingle, it torments and teases the said morain very sufficiently, and without intermission. It is always moving it on, and melting from under it, and one stone is always toppling, or tilting, or sliding over another, and one company of stones crashing over another, with staggering shift of heap behind. Now, leaving out of all account the pulverulent effect of original precipitation to glacier level from two or three thousand feet above, let the reader imagine a mass of sharp granite road-metal and paving-stones, mixed up with boulders of any size he can think of, and with wreck of softer rocks (micaceous schists in quantities, usually), the whole, say, half a quarter of a mile wide, and of variable thickness, from mere skin-deep mock-moraine on mounds of unsuspected ice--treacherous, shadow-begotten--to a railroad embankment, _passenger_-embankment, one eternal collapse of unconditional ruin, rotten to its heart with frost and thaw (in regions on the edge of each), and withering sun and waste of oozing ice; fancy all this heaved and shovelled, slowly, by a gang of a thousand Irish laborers, twenty miles downhill. You will conjecture there may be some dust developed on the way?--some at the hill bottom? Yet thus you will have but a dim idea of the daily and final results of the movements of glacier moraines--beautiful result in granite and slate dust, delivered by the torrent at last in banks of black and white slime, recovering itself, far away, into fruitful fields, and level floor for human life.

Now all this is utterly independent of any action whatsoever by the ice on its sustaining rocks. It _has_ an action on these indeed; but of this limited nature as compared with that of water. A stone at the bottom of a stream, or deep-sea current, necessarily and always presses on the bottom with the weight of the column of water above it--plus the excess of its own weight above that of a bulk of water equal to its own; but a stone under a glacier may be hitched or suspended in the ice itself for long spaces, not touching bottom at all. When dropped at last, the weight of ice may not come upon it for years, for that weight is only carried on certain spaces of the rock bed; and in those very spaces the utmost a stone can do is to press on the bottom with the force necessary to drive the given stone into ice of a given density (usually porous); and, with this maximum pressure, to move at the maximum rate of about a third of an inch in a quarter of an hour! Try to saw a piece of marble through (with edge of iron, not of soppy ice, for saw, and with sharp flint sand for felspar slime), and move your saw at the rate of an inch in three-quarters of an hour, and see what lively and progressive work you will make of it!

I say “a piece of marble;” but your permanent glacier-bottom is rarely so soft--for a glacier, though it acts slowly by friction, can act vigorously by dead-weight on a soft rock, and (with fall previously provided for it) can clear masses of that out of the way, to some purpose. There is a notable instance of this in the rock of which your correspondent speaks, under the Glacier des Bois. His idea, that the glacier is deep above and thins out below, is a curious instance of the misconception of glacier nature, from which all that Forbes has done cannot yet quite clear the public mind, nor even the geological mind. A glacier never, in a large sense, thins out at all as it expires. It flows level everywhere for its own part, and never slopes but down a slope, as a rapid in water. Pour out a pot of the thickest old white candied, but still fluent, honey you can buy, over a heap of stones, arranged as you like, to imitate rocks.[165] Whatever the honey does on a small scale, the glacier does on a large; and you may thus steady the glacier phenomena of current--though, of course, not those of structure or fissure--at your ease. But note this specially: When the honey is at last at rest, in whatever form it has taken, you will see it terminates in tongues with low rounded edges. The possible height of these edges, in any fluid, varies as its viscosity; it is some quarter of an inch or so in water on dry ground; the most fluent ice wall stand at about a hundred feet. Next, from this outer edge of the stagnant honey, delicately skim or thin off a little at the top, and see what it will do. It will not stand in an inclined plane, but fill itself up again to a level from behind. Glacier ice does exactly the same thing; and this filling in from behind is done so subtly and delicately, that, every winter, the whole glacier surface rises to replace the summer’s waste, not with progressive wave, as “twice a day the Severn fills;” but with silent, level insurrection, as of ocean-tide, the gray sea-crystal passes by. And all the structural phenomena of the ice are modified by this mysterious action.

Your correspondent is also not aware that the Glacier des Bois gives a very practical and outspoken proof of its shallowness opposite the Montanvert. Very often its torrent, under wilful touch of Lucina-sceptre, leaps to the light at the top of the rocks instead of their base.[166] That fiery Arveron, sometimes, hearing from reconnoitring streamlets of a nearer way down to the valley than the rounded ice-curve under the Chapeau, fairly takes bit in teeth, and flings itself out over the brow of the rocks, and down a ravine in them, in the wildest cataract of white thunder-clouds (endless in thunder, and with quiet fragments of rainbow for lightning), that I have ever blinded myself in the skirts of.

These bare rocks, over which the main river sometimes falls (and outlying streamlets always) are of firm-grained, massively rounded gneiss. Above them, I have no doubt, once extended the upper covering of fibrous and amianthoidal schist, which forms the greater part of the south-eastern flank of the valley of Chamouni. The schistose gneiss is continuous in direction of bed, with the harder gneiss below. But the outer portion is soft, the inner hard, and more granitic. This outer portion the descending glaciers have always stripped right off down to the hard gneiss below, and in places, as immediately above the Montanvert (and elsewhere at the brows of the valley), the beds of schistose gneiss are crushed and bent outwards in a mass (I believe) by the weight of the old glacier, for some fifty feet within their surface. This looks like work; and work of this sort, when it had to be done, the glaciers were well up to, bearing down such soft masses as a strong man bends a poplar sapling; but by steady push far more than by friction. You may bend or break your sapling with bare hands, but try to rub its bark off with your bare hands!

When once the ice, _with strength always dependent on pre-existent precipice_, has cleared such obstacles out of its way, and made its bed to its liking, there is an end to its manifest and effectively sculptural power. I do not believe the Glacier des Bois has done more against some of the granite surfaces beneath it, for these four thousand years, than the drifts of desert sand have done on Sinai. Be that as it may, its power of excavation on a level is proved, as I showed in my last letter, to be zero. Your correspondent thinks the glacier power vanishes towards the extremity; but as long as the ice exists, it has the same progressive energy, and, indeed, sometimes, with the quite terminal nose of it, will plough a piece of ground scientifically enough; but it never digs a hole: the stream always comes from under it full speed downhill. Now, whatever the dimensions of a glacier, if it dug a big hole, like the Lake of Geneva, when it was big, it would dig a little hole when it was little--(not that this is _always_ safe logic, for a little stone will dig in a glacier, and a large one build; but it is safe within general limits)--which it never does, nor can, but subsides gladly into any hole prepared for it in a quite placid manner, for all its fierce looks.

I find it difficult to stop, for your correspondent, little as he thinks it, has put me on my own ground. I was _forced_ to write upon Art by an accident (the public abuse of Turner) when I was two-and-twenty; but I had written a “Mineralogical Dictionary” as far as C, and invented a shorthand symbolism for crystalline forms, before I was fourteen: and have been at stony work ever since, as I could find time, silently, not caring to speak much till the chemists had given me more help.[167] For, indeed, I strive, as far as may be, not to speak of anything till I know it; and in that matter of Political Economy also (though forced in like manner to write of that by unendurable circumfluent fallacy), I know my ground; and if your present correspondent, or any other, will meet me fairly, I will give them uttermost satisfaction upon any point they doubt. There is free challenge: and in the knight of Snowdoun’s vows (looking first carefully to see that the rock be not a glacier boulder),

“This rock shall fly From its firm base, as soon as I.”

J. RUSKIN.[168]

[From “The Reader,” December 3, 1864.]

_ENGLISH_ VERSUS _ALPINE GEOLOGY._

DENMARK HILL, 29_th Nov._

I scarcely know what reply to make, or whether it is necessary to reply at all, to the letter of Mr. Jukes in your last number. There is no antagonism between his views and mine, though he seems heartily to desire that there should be, and with no conceivable motive but to obtain some appearance of it suppresses the latter half of the sentence he quotes from my letter.[169] It is true that he writes in willing ignorance of the Alps, and I in unwilling ignorance of the Wicklow hills; but the only consequent discrepancy of thought or of impression between us is, that Mr. Jukes, examining (by his own account) very old hills, which have been all but washed away to nothing, naturally, and rightly, attributes their present form, or want of form, to their prolonged ablutions, while I, examining new and lofty hills, of which, though much has been carried away, much is still left, as naturally and rightly ascribe a great part of their aspect to the modes of their elevation. The Alp-bred geologist has, however, this advantage, that (especially if he happen at spare times to have been interested in manual arts) he can hardly overlook the effects of denudation on a mountain-chain which sustains Venice on the delta of one of its torrents, and Antwerp on that of another; but the English geologist, however practised in the detection and measurement of faults filled in by cubes of fluor, may be pardoned for dimly appreciating the structure of a district in which a people strong enough to lay the foundation of the liberties of Europe in a single battle,[170] was educated in a fissure of the Lower Chalk.

I think, however, that, if Mr. Jukes can succeed in allaying his feverish thirst for battle, he will wish to withdraw the fourth paragraph of his letter,[171] and, as a general formula, even the scheme which it introduces. That scheme, sufficiently accurate as an expression of one cycle of geological action, contains little more than was known to all leading geologists five-and-twenty years ago, when I was working hard under Dr. Buckland at Oxford;[172] and it is so curiously unworthy of the present state of geological science, that I believe its author, in his calmer moments, will not wish to attach his name to an attempt at generalization at once so narrow, and so audacious. My experience of mountain-form is probably as much more extended than his, as my disposition to generalize respecting; it is less;[173] and, although indeed the apparent limitation of the statement which he half quotes (probably owing to his general love of denudation) from my last letter, to the chain of the Alps, was intended only to attach to the words “quite visibly,” yet, had I myself expanded that statement, I should not have assumed the existence of a sea, to relieve me from the difficulty of accounting for the existence of a lake; I should not have assumed that all mountain-formations of investiture were marine; nor claimed the possession of a great series of stratified rocks without inquiring where they were to come from. I should not have thought “even more than one” an adequate expression for the possible number of elevations and depressions which may have taken place since the beginning of time on the mountain-chains of the world; nor thought myself capable of compressing into Ten Articles, or even into Thirty-nine, my conceptions of the working of the Power which led forth the little hills like lambs, while it rent or established the foundations of the earth; and set their birth-seal on the forehead of each in the infinitudes of aspect and of function which range between the violet-dyed banks of Thames and Seine, and the vexed Fury-Tower of Cotopaxi.

Not but that large generalizations are, indeed, possible with respect to the diluvial phenomena, among which my antagonist has pursued his--(scarcely amphibious?)--investigations. The effects of denudation and deposition are unvarying everywhere, and have been watched with terror and gratitude in all ages. In physical mythology they gave tusk to the Grææ, claw to the Gorgons, bull’s frontlet to the floods of Aufidus and Po. They gave weapons to the wars of Titans against Gods, and lifeless seed of life into the hand of Deucalion. Herodotus “rightly spelled” of them, where the lotus rose from the dust of Nile and leaned upon its dew; Plato rightly dreamed of them in his great vision of the disrobing of the Acropolis to its naked marble; the keen eye of Horace, half poet’s, half farmer’s (albeit unaided by theodolite), recognized them alike where the risen brooks of Vallombrosa, amidst the mountain-clamors, tossed their champed shingle to the Etrurian sea, and in the uncoveted wealth of the pastures,

“Quæ Liris quietâ; _Mordet_ aquâ, taciturnus amnis.”[174]

But the inner structure of the mountain-chains is as varied as their substance; and to this day, in some of its mightier developments, so little understood, that my Neptunian opponent himself, in his address delivered at Cambridge in 1862, speaks of an arrangement of strata which it is difficult to traverse ten miles of Alpine limestone without finding an example of, as beyond the limits of theoretical imagination.[175]

I feel tempted to say more; but I have at present little time even for useful, and none for wanton, controversy. Whatever information Mr. Jukes can afford me on these subjects (and I do not doubt he can afford me much), I am ready to receive, not only without need of his entreaty, but with sincere thanks. If he likes to try his powers of sight, “as corrected by the laborious use of the protractor,” against mine, I will in humility abide the issue. But at present the question before the house is, as I understand it, simply whether glaciers excavate lake-basins or not. That, in spite of measurement and survey, here or elsewhere, seems to remain a question. May we answer the first, if answerable? That determined, I think I might furnish some other grounds of debate in this notable cause of Peebles against Plainstanes, provided that Mr. Jukes will not in future think his seniority gives him the right to answer me with disparagement instead of instruction, and will bear with the English “student’s” weakness, which induces me, usually, to wish rather to begin by shooting my elephant than end by describing it out of my moral consciousness.[176]

J. RUSKIN.

[From “The Reader,” December 10, 1864.]

_CONCERNING HYDROSTATICS._

NORWICH, 5_th December._

Your pages are not, I presume, intended for the dissemination of the elements of physical science. Your correspondent “M. A. C.” has a good wit, and, by purchasing any common treatise on the barometer, may discover the propriety of exercising it on subjects with which he is acquainted. “G. M.” deserves more attention, the confusion in his mind between increase of pressure and increase of density being a very common one.[177] It may be enough to note for him, and for those of your readers whom his letter may have embarrassed, that in any incompressible liquid a body of greater specific gravity than the liquid will sink to any depth, because the column which it forms, together with the vertical column of the liquid above it, always exceeds in total weight the column formed by the equal bulk of the liquid at its side, and the vertical column of liquid above that. Deep-sea soundings would be otherwise impossible. “G. M.” may find the explanation of the other phenomena to which he alludes in any elementary work on hydrostatics, and will discover on a little reflection that the statement in my last letter[178] is simply true. Expanded, it is merely that, when we throw a stone into water, we substitute pressure of stone-surface for pressure of water-surface throughout the area of horizontal contact of the stone with the ground, and add the excess of the stone’s weight over that of an equal bulk of water.

It is, however, very difficult for me to understand how any person so totally ignorant of every circumstance of glacial locality and action, as “G. M.” shows himself to be in the paragraph beginning “It is very evident,” could have had the courage to write a syllable on the subject. I will waste no time in reply, but will only assure him (with reference to his assertion that I “get rid of the rocks,” etc.), that I never desire to get rid of anything but error, and that I should be the last person to desire to get rid of the glacial agency by friction, as I was, I believe, the first to reduce to a diagram the probable stages of its operation on the bases of the higher Alpine aiguilles.[179]

Permit me to add, in conclusion, that in future I can take no notice of any letters to which the writers do not think fit to attach their names. There can be no need of initials in scientific discussion, except to shield incompetence or license discourtesy.

J. RUSKIN.

[From “Rendu’s Theory of the Glaciers of Savoy,” Macmillan, 1874.]

_JAMES DAVID FORBES: HIS REAL GREATNESS.[180]_

The incidental passage in “Fors,” hastily written, on a contemptible issue, does not in the least indicate my sense of the real position of James Forbes among the men of his day. I have asked his son’s[181] permission to add a few words expressive of my deeper feelings.

For indeed it seems to me that all these questions as to priority of ideas or observations are beneath debate among noble persons. What a man like Forbes first noticed, or demonstrated, is of no real moment to his memory. What he was, and how he taught, is of consummate moment. The actuality of his personal power, the sincerity and wisdom of his constant teaching, need no applause from the love they justly gained, and can sustain no diminution from hostility; for their proper honor is in their usefulness. To a man of no essential power, the accident of a discovery is apotheosis; to _him_, the former knowledge of all the sages of earth is as though it were not; he calls the ants of his own generation round him, to observe how he flourishes in his tiny forceps the grain of sand he has imposed upon Pelion. But from all such vindication of the claims of Forbes to mere discovery, I, his friend, would, for my own part, proudly abstain. I do not in the slightest degree care whether he was the first to see this, or the first to say that, or how many common persons had seen or said as much before. What I rejoice in knowing of him is that he had clear eyes and open heart for all things and deeds appertaining to his life; that whatever he discerned, was discerned impartially; what he said, was said securely; and that in all functions of thought, experiment, or communication, he was sure to be eventually right, and serviceable to mankind, whether out of the treasury of eternal knowledge he brought forth things new or old.

This is the essential difference between the work of men of true genius and the agitation of temporary and popular power. The first root of their usefulness is in subjection of their vanity to their purpose. It is not in calibre or range of intellect that men vitally differ; every phase of mental character has honorable office; but the vital difference between the strong and the weak--or let me say rather, between the availing and valueless intelligence--is in the relation of the love of self to the love of the subject or occupation. Many an Alpine traveller, many a busy man of science, volubly represent to us their pleasure in the Alps; but I scarcely recognize one who would not willingly see them all ground down into gravel, on condition of his being the first to exhibit a pebble of it at the Royal Institution. Whereas it may be felt in any single page of Forbes’ writing, or De Saussure’s, that they love crag and glacier for their own sake’s sake; that they question their secrets in reverent and solemn thirst: not at all that they may communicate them at breakfast to the readers of the Daily News--and that, although there were no news, no institutions, no leading articles, no medals, no money, and no mob, in the world, these men would still labor, and be glad, though all their knowledge was to rest with them at last in the silence of the snows, or only to be taught to peasant children sitting in the shade of pines.

And whatever Forbes did or spoke during his noble life was in this manner patiently and permanently true. The passage of his lectures in which he shows the folly of Macaulay’s assertion that “The giants of one generation are the pigmies of the next,”[182] beautiful in itself, is more interesting yet in the indication it gives of the general grasp and melodious tone of Forbes’ _reverent_ intellect, as opposed to the discordant insolence of modernism. His mind grew and took color like an Alpine flower, rooted on rock, and perennial in flower; while Macaulay’s swelled like a puff-ball in an unwholesome pasture, and projected itself far round in deleterious dust.

I had intended saying a few words more touching the difference in temper, and probity of heart, between Forbes and Agassiz, as manifested in the documents now[183] laid before the public. And as far as my own feelings are concerned, the death of Agassiz[184] would not have caused my withholding a word. For in all utterance of blame or praise, I have striven always to be kind to the living--just to the dead. But in deference to the wish of the son of Forbes, I keep silence: I willingly leave sentence to be pronounced by time, above their two graves.

JOHN RUSKIN.

The following letters,[185] one from Forbes to myself, written ten years ago, and the other from one of his pupils, received by me a few weeks since, must, however, take their due place among the other evidence on which such judgment is to be given.

J. R.