52 



NATURE 



\^Nov. 20, 1873 



though even there, where this connection is so clear, we 

 should see at the same time how greatly the tops and sides 

 of the long saddle-shaped arches of rock have suffered 

 from subsequent waste. But among the contorted, in- 

 verted, and broken rocks of the Central Alps the task 

 would be infinitely more difficult. 



We could not advance far, however, in such a quest 

 before observing that one feature stands out conspicu- 

 ously enough among the mountains, viz., that whatever 

 might have been their original outlines, these were most 

 certainly not the same as those which we see to-day. No 

 part of the history of the ground can be made more self- 

 evident than that, since the birth of these mountains, 

 millions upon millions of cubic yards of rock have been 

 worn off their crests and ridges, and carved out of their 

 sides. There is not a cliff, crag, or valley along the 

 whole chain of the Alps which does not bear witness to 

 this great truth. 



If then, even when dealing with the young Alps, we 

 cannot be quite sure what were their first or infant fea- 

 tures, how impossible must it be to decide as to the early 

 outUnes of such immensely more ancient uplands as those 

 which date from paheozoic tunes ! For, evidently, the 

 higher their antiquity, and the longer, therefore, their ex- 

 posure to ceaseless waste, the more must these outlines 

 be changed. The general mass of land might still re- 

 main land, but trenched and furrowed and worn down, as 

 the Alps are now suffering, until not a single vestige or 

 indication of its first contour survived, the remaining por- 

 tions being, as it were, merely the stump or base of what 

 once was. 



Now this is the position in which the question presents 

 itself in Britain. The hills of the Highlands and Southern 

 Uplands of Scotland, of the Lake district, and of Wales, 

 are not mountains in the same sense as the Alps or 

 Pyrenees, or other great continental mountain-chains. 

 However much these long lines of elevated ground may 

 have had their outlines modified by the universal waste of 

 the earth's surface, their linear character, the general 

 parallelism of their component ridges, the undulations of 

 the strata along their flanks, as well as their internal geo- 

 logical structure, bear witness to the fact that they are but 

 huge wrinkles upon the shrivelled globe— tracts which 

 have been thrust up while the neighbouring regions have 

 sunk down. But in Britain these characteristic features 

 are wanting. In all probability there never was any true 

 mountain-chain in our region. There is good reason to 

 believe that in very ancient times, that is to say, previous to 

 the Old Red sandstone, a wide plateau-like mass of land 

 was upraised on the north coast of Europe, surviving 

 portions of it being represented by the detached hilly 

 regions of Britain and the great table-land of Scandi- 

 navia. The rocks underlying this upheaved tract under- 

 went, at the time of elevation, enormous compression and 

 consequent contortion. This could not happen without 

 an infinite amount of resistance. The heat thus evolved 

 among the grinding masses may have been amply suffi- 

 cient even to melt them in part. And no doubt it was 

 during this process that they became crystalline over such 

 wide areas, and were injected with granite and other 

 melted products. But aU this had been wholly, or almost 

 wholly,complcted before the time of the Old Red sandstone, 

 for the deposits of that geological system are formed out 

 of the older altered rocks, and lie undisturbed upon them. 

 Even now, in spite of all the subsequent denudation, the 

 patches of old red conglomerate which remain show to 

 what an extent the older rocks had been butied under it, 

 for they are found rising here and there to a height of 

 2,000 or 3,000 ft. above the sea. But they prove further, 

 not only that the contortion of the underlying rocks pre- 

 ceded the Old Red sandstone, but that these rocks hxd 

 sufl'cred a vast extent of waste at the surface, before even 

 the oldest visible parts of the conglomerate were deposited 

 upon them. This waste has Iseen in progress ever since. 



We need not, therefore, hope to discover any vestige of 

 the aboriginal surface. A geological section drawn across 

 any part of the hills proves beyond question that the 

 general surface of the country has had hundreds or even 

 thousands of feet of solid rock worn away from it. Such 

 a section shows moreover that our present valleys are not 

 mere folds due to underground movements, but are really 

 trenches out of which the solid rock has been carried 

 away. 



So far, this is a question of simple fact, and not merely 

 of opinion. The language of Hutton maybe literally true 

 of Britain ; — " The mountains have been formed by the 

 hollowing out of the valleys, and the valleys have been 

 hollowed out by the attrition of hard materials coming 

 from the mountains." Our British hills, unlike the chains 

 of the Jura and the Alps, are simply irregular ridges de- 

 pending for their shape and trend upon the directions 

 taken by the separating valleys. The varying textures of 

 the rocks, their arrangements with relation to each other, 

 their foldings and fractures, and the other phenomena 

 comprised under what is termed " geological structure," 

 have greatly modified this result, but the process has 

 nevertheless, as I believe, been one of superficial sculp- 

 turing, and not of subterranean commotion and upheaval. 

 On the details of this process it is not needful to dwell. 



From these cursory statements, which express, I believe, 

 the general concurrent opinions of the modern Huttonian 

 school, it should be clear how far that school must be 

 from ignoring the influence of subterranean forces. 

 Hutton himself never did so, and his followers now know 

 far more of these forces than he did. But on the other 

 hand, they claim for the surface-agents in geology a 

 potency great enough to cut down table-lands into moun- 

 tain ridges and glens, to carve out the surface of the land 

 into systems of valleys, and in the end to waste a con- 

 tinent down to the level of the sea. 



{ To he cont-inucd.) 



ASTRONOMY AT OXFORD 



DR. DE LA RUE having, in the course of last sum- 

 mer, made a munificent ofter of several astro- 

 nomical instruments and apparatus, including a large 

 reflecting telescope, to the University, the subject was 

 brought under the consideration of the delegates of the 

 Museum, who, at their first meeting in this term, ap- 

 pointed a committee to " report on the desirability of 

 accepting the munificent offer of Dr. De La Rue to present 

 to the University his celebrated reflecting telescope, on 

 the probable cost of a building to receive the instrument, 

 and on the precise purposes for which this instrument 

 may be usefully employed, in distinction to the refracting 

 telescope now being set up." 



The committee, after full and careful examination of 

 the whole subject, have sent in a report, to which they 

 have unanimously agreed, and which the delegates re- 

 commended, with entire confidence, to tlie favourable 

 consideration of the council. In consequence of this 

 report, the following forms of decree will be submitted to 

 a convocation to be held on Thursday, Nov. 27 : — 



I. That the reflecting telescope and other apparatus 

 olfered to the University by Dr. De La Rue be accepted ; 

 and that the Vice-Chancellor be requested to return the 

 thanks of the University to Dr.De La Rue for hismunificent 

 gift. And that the curators of the University chest be autho- 

 rised to pay to the delegates of the University Museum a 

 sum not exceeding 1,500/., to be expended by them on the 

 erection of buildmgs in the park suitable for the reception 

 and use of the telescope and other apparatus presented by 

 Dr. De La Rue, as also of the instruments at present in the 

 small observatory on the east side of the museum, accor- 

 ding to plans and specifications prepared by Mr. Charles 

 Barry, architect, and adjoining the observatory now nearly 

 completed. 



