486 MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 



from 40 to 50 feet high, and running for half a mile in nearly a straight line (as 

 is the case in Liddesdale), or for nearly two miles in a curved line, as in the case 

 of Dogden Moss in Berwickshire ? * 



It is with the view of obviating these apparent objections, that glaciers have 

 been suggested ; as the agent which has produced the remarkable knolls and 

 ridges just referred to, and which is said to be in Switzerland at this moment 

 giving rise to phenomena exactly similar. 



But here, as it humbly appears to me, lies the fallacy of the explanation. I 

 do not believe that the accumulations of debris formed by glaciers, are exactly 

 similar to the knolls and ridges in this country above referred to. In outward 

 form they may be similar. Farther, they may often be in situations, precisely 

 analogous to those occupied by the moraines of Switzerland ; thotigh, assuredly, 

 they are also as often in situations, where no moraine, terminal, medial, or lateral, 

 is ever seen in Switzerland. But, in the internal structure of these gravel heaps, 

 and in the nature of the materials composing them, there appears to be a total 

 and entire dissimilarity. 



All the knolls and gravelly ridges which I have seen in the border counties, 

 contain stratified beds of sand and fine gravel, which seem to me unequivocally to 

 demonstrate, that they were deposited by water ; and by water which, judging 

 from the form and nature of the pebbles, must have rolled them from a great dis- 

 tance. Now, it would appear, that moraines have a totally different structure. 

 There are in them no stratified beds of sand or gravel ; and the fragments are ge- 

 nerally angular. Thus, AGASSIZ states (I quote from a very good abstract of his 

 views lately published by Mr MACLAREN, a Fellow of this Society), that " The ma- 

 terials of moraines are not stratified, but huddled together in confusion. The frag- 

 ments are generally somewhat rounded by mutual attrition ; but some are angu- 

 lar. They may be distinguished from the banks of gravel formed at the margin 

 of lakes, by their internal structure."! To the same effect, Mr CHARPENTIER, in 

 an article published in the last number of Professor JAMESON'S Journal, says, 

 " The sedimentary deposits, whether stratified deposits of pebbles, sand, or day, are, 

 in my opinion, not the erratic formation (formed by glaciers), but diluvium, that 

 is to say, a sediment whose materials have been conveyed and deposited by mater" 

 On the same page, he adds, that " erratic deposits can always be distinguished 

 from the diluvium, by the frequency of well preserved angular debris." 



If, then, according to the admission of the two greatest advocates of this 

 Theory, the accumulations of gravel formed by glaciers are characterized by 

 frequency of " angular debris ;" and if, as they also admit, stratified beds of 



* For an account and surface-plan of Dogden Moss Kaims, see Paper by me, published in the 

 Transactions of the Highland Society for 1836. 



t Glacial Theory, by Mr MACLAREN, p. 14. 



