[177] “M. A. C.” wrote “Concerning Stones,” and dealt—or attempted to deal—with “atmospheric pressure” in addition to the pressure of water alluded to in Mr. Ruskin’s letter of November 26. The letter signed “G. M.” was entitled “Mr. Ruskin on Glaciers;” see next note. Both letters appeared in the Reader of December 3, 1864.
[178] Not in the “last letter,” but in the last but one—see ante, p. 177, “A stone at the bottom of a stream,” etc. The parts of “G. M.’s” letter specially alluded to by Mr. Ruskin are as follows:
“It is very evident that the nearer the source of the glacier, the steeper will be the angle at which it advances from above, and the greater its power of excavation.... Mr. Ruskin gets rid of the rocks and débris on the under side of the glacier by supposing that they are pressed beyond the range of action in the solid body of the ice; but there must be a limit to this, however soft the matrix.”
[179] See “Modern Painters,” Part v., chap. 13, “On the Sculpture Mountains,” vol. iv. p. 174.
[180] In connection with the question of glacier-motion, Mr. Ruskin’s estimate of Professor Forbes and his work is here reprinted from Rendu’s “Glaciers of Savoy” (Macmillan, 1874), pp. 205-207. For a passage on the same subject which was reprinted in the “Glaciers of Savoy,” in addition to the new matter republished here, and for a statement of the course of glacier-science, and the relation of Forbes to Agassiz, the reader is referred to “Fors Clavigera,” 1873, Letter 34, pp. 17-26. The “incidental passage” consists of a review of Professor Tyndall’s “Forms of Water” (London, 1872), and the “contemptible issue” was that of his position and Forbes’ amongst geological discoverers.
[181] George Forbes, B.A., Professor of Natural Philosophy in the Andersonian University, Glasgow, and editor of “The Glaciers of Savoy.”
[182] This saying of Macaulay’s occurred in an address which, as M.P. for that city, he delivered at the opening of the Edinburgh Philosophical Institution, 1846 (Nov. 4). Forbes’ criticism of it and of the whole address may be found in a lecture introductory to a course on Natural Philosophy, delivered before the University of Edinburgh (Nov. 1 and 2, 1848), and entitled “The Danger of Superficial Knowledge;” under which title it was afterwards printed, together with a newspaper report of Macaulay’s address (London and Edinburgh, 1849). In the edition of Macaulay’s speeches revised by himself, the sentence in question is omitted, though others of a like nature, such as “The profundity of one age is the shallowness of the next,” are retained, and the whole argument of the address remains the same. (See Macaulay’s Works, 8 vol. ed., Longmans, 1866. Vol. viii. p. 380, “The Literature of Great Britain.”) For a second mention of this saying by Mr. Ruskin, see also “Remarks addressed to the Mansfield Art Night Class,” 1873, now reprinted in “A Joy for Ever” (Ruskin’s Works, vol. xi. p. 201).
The following are parts of the passage (extending over some pages) in Forbes’ lecture alluded to by Mr. Ruskin:
“How false, then, as well as arrogant, is the self-gratulation of those, who, forgetful of the struggles and painful efforts by which knowledge is increased, would place themselves, by virtue of their borrowed acquirements, in the same elevated position with their great teachers—nay, who, perceiving the dimness of light and feebleness of grasp, with which, often at first, great truths have been perceived and held, find food for pride in the superior clearness of their vision and tenacity of their apprehension!” Then, after quoting some words from Dr. Whewell’s “Philosophy of the Inductive Sciences,” vol. ii. p. 525, and after some further remarks, the lecturer thus continued: “The activity of mind, the earnestness, the struggle after truth, the hopeless perplexity breaking up gradually into the fulness of perfect apprehension,—the dread of error, the victory over the imagination in discarding hypotheses, the sense of weakness and humility arising from repeated disappointments, the yearnings after a fuller revelation, and the sure conviction which attends the final advent of knowledge sought amidst difficulties and disappointments,—these are the lessons and the rewards of the discoverers who first put truth within our reach, but of which we who receive it at second hand can form but a faint and lifeless conception.” (See pp. 39-41 of “The Danger of Superficial Knowledge.”)
[183] In the edition of Rendu’s “Glaciers of Savoy” already alluded to.