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, 5th 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]