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ADDENDA. 



on the Revolutions of the Earth's Surface : — a case which has always 

 appeared to me to be the strongest ever adduced in favour of the theory 

 of an overwhelming debacle having rushed, at least in that country, over 

 hill and valley. The furrows and scratches in the same district are 

 parallel to each other, and hence run in the same direction : — thus, near 

 Edinburgh, they extend in a line a little north of west and south of east, 

 that is parallel to the valley of the estuary ; but both to the eastward and 

 westward they deviate from this line by more than half a right angle ; and 

 on the south-west part of Scotland they have no uniform direction. 

 In the north of Scotland, however, near Brora, Mr. Murchison {Geolog. 

 Transact. 2d Series, vol. ii., p. 357) found the hills marked in parallel 

 lines, directed north-west and south-east. The furrows and scratches 

 near Edinburgh seem generally to traverse the less inclined surfaces, but 

 Sir James, speaking of one part, says " the perpendicular face as well as 

 the rest is covered with lines, which are horizontal, or nearly so." In 

 these respects the case appears very similar to that of the Alps : the 

 rocks, however, are not polished ;* but this may be owing to their nature, 

 sandstone and trap, and not to any difference in the cause ; for Dr. 

 Richardson tells me that in the same rivers in North America, in which 

 the granitic rocks are much polished, those of laminated limestone are 

 not at all so. Near Edinburgh, where the lines extend west and east, 

 the v/estern face of the hills (of which the highest mentioned is four 

 hundred and seventy feet above the sea) is chiefly marked, whilst on the 

 opposite or protected side, a long tail of (so called) diluvium extends, 

 which consists of blue clay, with large erratic boulders embedded in it. 

 These boulders, as I am informed by Mr. James Hall, and by Mr. Smith 

 of Jordanhill, are themselves marked with parallel lines, having one 

 direction, which shows that they were held fast whilst drifted across the 

 country, and not rolled over and over, like a pebble in a stream. It is 



of glaciers in the Alps and in other regions of central Europe, excepting 

 at great altitudes ; and from such situations a debacle was absolutely 

 requisite to transport fragments on ice. Sir James rejects the belief of 

 M, Wrede (given on the authority of De Luc), that the boulders of the 

 Baltic may have been brought into their present place by ice, acting, 

 during a steady and slow change in the level of the ocean. M. Wrede, 

 therefore, appears to have been the originator of the theory advocated in 

 this volume ; and no country was more likely than Sweden to have given 

 birth to such a theory. 



* It is, however, said in Professor Buckland's Ecliquice DiluviancBy 

 p. 202, that Colonel Imrie found the surface of some trap-rocks in the 

 southern parts of Stirlingshire, having " a considerable degree of polish ; 

 and this polish is almost always seen marked by long linear scratches." 



