^9 



the dli*ecfc Control of geometrical adnieasureiUent, and has shown 

 that such lines, when correctly examined, are neither horizontal nor 

 parallel, so is it my duty, believing that many of the Scottish gravel 

 terraces have been produced by similar agency, to incite my brother 

 geologists to apply the rigorous method of examination of M. Bravais, 

 and thus to render this branch of our inquiries more exact. I en- 

 tertain, indeed, the most sanguine hope, that before another anni- 

 versary passes over, the Scottish phcenomena will be tested in a 

 similar manner with those of Norway ; and, that as the beds of marine 

 shells in England and parts of Scotland and Ireland so clearly be- 

 speak great irregularities of movement in the land, so shall we be 

 equally able to show that in the Highlands, lines of elevation acting 

 from different centres and with different degrees of intensity, have 

 raised former sea-bottoms to the different levels at which we now find 

 them, whether along shores or in the deep lateral depressions by 

 which Scotland is so fissured. Let the memoir of M. Bravais there- 

 fore, with the admirable commentary of M. Elie de Beaumont, be the 

 stimulus to those who enter upon this inquiry, which should not be 

 limited to the parallel roads of Glen Roy, but extended to the Western 

 Islands and shores of the lochs of Western Ross, among which I 

 have a recollection of numerous shingle terraces, including that 

 so well described by Captain Vetch*; and eastwards, to the great 

 accumulations adverted to on the southern shores of the Moray 

 Frith, which in their turn should be connected with the elevated 

 shelly beaches of Banffshire, first pointed out by Mr. Prestwichf . 



In quitting the Consideration of this very interesting topic, I cannot 

 however occupy this Chair Avithout saying, that albeit British geolo- 

 gists have not yet employed the rigorous test applied by M. Bravais, 

 there is no department of our science on which their observations 

 have thrown more light than that which embraces the phsenomena 

 of ancient sea-beaches. Reasoning backwards from existing causes 

 and the facts of yesterday, Mr. Lyell has, by a well-digested set of 

 observations, led us to contemplate the very period when the ocean 

 was beating against our inland escarpments of chalk, and when our 

 valleys and those of the opposite coasts of France may have been 

 fiords like those of Norway t- 



I also know that my friend Mr. Lonsdale has long entertained 

 similar views, derived from his intimate acquaintance with the 

 escarpment of the oolitic strata ; along some of which he has ob- 

 served as perfect lines of dunes as those upon the sea-coast of 

 France, whilst in others he has been struck with their resemblance 

 to many great dislocations of marine undercliffs, whereby masses 

 of the inferior oolite have been pitched into inclined positions at the 

 bottom of the adjacent valleys; and as I know that this subject is 

 one which now occupies his attention, I have strong hopes that by 

 his present residence on the coast of Devonshire, he will be enabled 



• Geol. Trans, vol. i. p. 416. 



■f M. de Beaumont makes full allusion to the British cases. 



J Elements of Geology, vol. ii. pp. 3 — 8; 



