5° 



NA TURE 



\Nov. 20, 1873 



EA R TH -SCULP TURE * 



AMONG the questions which may be treated as mat- 

 ters of strict science, and which yet cannot be 

 wholly divested of the strong human, one might almost say 

 personal, interest which belongs to them, is the birth of 

 mountains and valleys. The familiar outhnes of his 

 dwelling-place have fixed the attention of man from the 

 infancy of the race up to the present day. Long before 

 science arose to deal with them they had become inwoven 

 with his history, his habits, and his creed. The great 

 mountains had been to him emblems of majesty and 

 eternity, lifting up their fronts to heaven as they had 

 done from the beginning, and would no doubt do to the 

 end. They rose before hmi as monuments of the power 

 of that great Being who had heaved them out of chaos. 

 It was enough for him in that early time to feel their 

 mighty influences ; he had then no questions or doubts as 

 to how or when they first appeared upon the earth. 



Happily, in spite of questioning, e.xacting Science, these 

 first natural and instinctive feelings are not yet dead 

 within us. A knowledge even of all the laws of moun- 

 tain-making cannot, if our minds are healthy and our 

 hearts beat true, deprive us wholly of that first genuine 

 child-like awe and wonder in presence of noble moun- 

 tains, — crag and cliff sweeping in rugged and colossal 

 massiveness above dark waves of pine, far into the keen 

 and clear blue air ; — the vast mantle of snow, so cloud- 

 like in its brightness, yet thrown in many a solid fold 

 over crest and shoulder ; the dark spires and splintered 

 peaks, half snow, half stone, rising into the sky, like very 

 pillars of heaven ; and then the verdure of the valleys 

 below, the dash of waterfalls, the plenteous gush of 

 springs, the laugh and dance of brook and river as they 

 one and all hurry down to the plains— who can see these 

 things for the first time, nay, for the hundredth time, 

 without at least some sparkle of the simple child-like 

 emotion of the olden time, or without appreciating, even 

 if he cannot fully share, the feeling of the poet to whom 

 they bring " dim eyes suffused with tears " ? 



These great dominant features of the land must indeed 

 ever rivet our imagination, and yet when the questioning 

 spirit of modern science asks to know how they came 

 into being, we are no longer permitted to content ourselves 

 with the early belief that they were but parts of the 

 primaeval outhnes of the earth. The progress of inquiry 

 and knowledge has destroyed th.at belief. We find, too, 

 that both laboin- and patience are needed ere we can un- 

 derstand what has been put in its place. But the task of 

 learning this is well repaid. However grandly the moun- 

 tains rose when they were gazed at only in awe and 

 wonder, they gain an added sublimity when the eyes 

 which look upon them can trace some of the steps where- 

 by their grim magnificence has been achieved. 



We naturally associate the more lofty and rugged parts 

 of the land with the operations of former earthquakes 

 and convulsions by which the solid earth has been 

 broken and ridged into these picturesque forms. This 

 obvious inference was early adopted in geology, and 

 though in many cases a mere belief rather than a legiti- 

 mate deduction from observation, and springing from a 

 conviction of what ought to be, rather than what has 

 been proved to be the case, it has sturdily maintained 

 its hold alike on the popular mind, and also to a very 

 considerable extent in the orthodox geological creed. 



Towards the end of last century, however, Hutton and 

 Playfair, names never to be mentioned in Edinburgh 

 without gratitude and pride, proclaimed views of a very 

 different character. They maintained that the rocks of 

 the land, originally accumulated under the sea, have 

 been upheaved by underground movements, and with- 

 out pretending to know in what external forms these 



» The Opening Address foi- the Session 1873-4 to the Edinburgh Geological 

 Society, delivered Thursday, Nov. 6, by the President, Prof. Geikie, F.R.S. 



rocks first ajjpeared above the sea, they contended that 

 the present contours of the land had arisen mainly from 

 a process of sculpture,— the valleys having been carved 

 out by rains, streams, and other superficial agents, while 

 the hills were left standing up as ridges between. So 

 satisfied were these bold and clear-sighted men that their 

 idea was essentially true, that they gave themselves no 

 concern in gathering detailed proofs in its support. They 

 were content with general appeals to the face of nature 

 everywhere as their best and irrefragable witness. But, 

 as events proved, they were in advance of their time. 

 The views which they promulgated on this subject were 

 first opposed, then laid aside and forgotten. In the sub- 

 sequent literature of the science for fully half a century 

 they almost wholly disappear. An occasional reference 

 to them may be met with, where, however, they are cited 

 only to be dismissed, as if the writer seemed hardly able 

 to restrain some expression of his wonder that men could 

 ever have been found so Quixotic as to vent such notions, 

 or that others could have been so gullible as to believe 

 them. 



Apart altogether from the truth or error of the Hut- 

 tonian teaching regarding the origin of the earth's super- 

 ficial features, no one who has the progress of geology at 

 heart can regard without regret this almost contemptuous 

 dismissal of the question from the range of scientific in- 

 quiry. For together with that teaching went all interest 

 in, and even all intelligent appreciation of, the problem 

 which Hutton had set himself to solve. Men turned 

 back to vague notions about cataclysms, earthquakes, 

 subterranean convulsions and fractures, of which they 

 spoke, and sometimes still speak, with a boldness in inverse 

 proportion to their knowledge of the actual conditions of 

 the problem. They studied with praiseworthy assiduity 

 and success the working of the various natural agents 

 whereby the surface of the land is affected, but it was 

 with the view rather of showing how the materials of new 

 continents are gathered together, than of learning how 

 the outlines of existing continents have been produced. 

 The study of the origin of mountain and valley went out 

 of fashion, and from the time of Playfair's Illustrations, 

 published at the beginning of this century, received in 

 this country but scant and haphazard attention until in 

 recent years the subject has gradually revived, and has 

 become one of the most prominent and interesting sub- 

 jects of geological research. 



It is not my purpose to give any historical sketch of 

 the progress of inquiry on this question, although I ought 

 not even to refer to it without an allusion to the names 

 of Scrope, Ramsay, Jukes, Ruskin, Dana, Topley, 

 Whitaker, Greenwood, the Duke of Argyll, Mackintosh, 

 and others, who, though often differing widely in their 

 views, have done so much to renew an interest in what 

 will probably always prove one of the most alluring 

 aspects of geology. Thoroughly convinced of the essen- 

 tial truth on which the Huttonian doctrines were based I 

 wish, on the present occasion, first to define and illustrate 

 some of the leading features of these doctrines as I hold 

 them myself, and as I believe them to be held by the 

 great body of active field geologists in Britain, and 

 secondly, to review certain objections which have recently 

 been reiterated against them. 



At the outset it is necessary to ascertain what relation 

 the internal arrangements of the rocks bear to the ex- 

 ternal forms of the land, in other words, the influence of 

 what is called Geological Structure. It is obvious, as 

 Hutton showed, that since the rocks have been formed as 

 a whole under the sea, they must have been raised out of 

 that original position into land, so that the first point we 

 settle beyond dispute is that the mass of the land owes its 

 existence to upheaval from below. But though we fix 

 securely enough this starting point in our inquirj', it by 

 no means follows that we thereby settle what was the 

 original outline of the land so upheaved. The non- 



