of the Shetland Inlands. 69 



gneisses and scliists are met with to the west of the fault. And so 

 also in the island of Papa Stour numerous striated blocks of the 

 altered Old Red rocks from Sandness Hill are commingled in the 

 moraine profonde with fragments of the local porphyry and contem- 

 poraneous diabase porphyrites, while in the neighbourhood of Melby 

 the Boulder-clay sections may be searched in vain for blocks derived 

 from Papa Stour. It requires only a moment's reflection to see that 

 the phenomena would have been precisely the reverse of what we have 

 just described, had the ice-movement heen from the north-west, as 

 Mr. Milne Home imagines. Indeed, as we stated in our paper, " the 

 evidence obtained from the Boulder-clay along these lines of section 

 completely refutes the theory that these north-westerly striae 

 could have been produced by ice coming from the North Atlantic." 



Mr. Milne Home concludes his review by stating that " the authors 

 of this paper, besides maintaining that the Shetlands were glaciated 

 by a mer de glace from Scandinavia, have gone so far as to suggest 

 that the whole of Scotland underwent a glacial invasion from the 

 same quarter ; and they give reasons for this opinion which are not 

 very intelligible." 



The only ground for this statement is the following sentence in 

 the conclusion of our paper ; " The land-ice which glaciated Scotland 

 could only have come from Scandinavia, as the striated surfaces clearly 

 point in that direction." Owing to an unfortunate printer's error, tor 

 which we are sorry, the word Scotland in the foregoing sentence has 

 been substituted for Shetland ; ah error which is self-evident to 

 any ordinary reader after a careful perusal of the context. We do 

 not believe that any part of Scotland was ever over-ridden by the 

 Scandinavian mer de glace ; indeed, there is not the slightest evidence 

 in support of such an hypothesis. So far from this being the case, we 

 have advanced sufficient evidence to prove that the Scotch ice-sheet 

 must have spread far enough over the floor of the North Sea as to 

 over-ride the Orkney Islands.^ 



We have now disposed of the various points in this address which 

 are likely to mislead the general reader. We have spent our annual 

 holidays for four years in working out the glacial phenomena of 

 Shetland, Orkney and Caithness, with a view to determine the 

 question of the extension of the ice in the North Sea during the 

 Glacial period. In the course of these traverses we have amassed 

 a great amount of detailed evidence, which cannot readily be in- 

 corporated in the pages of a scientific publication like the Quarterly 

 Journal of the Geological Society. We have had to content our- 

 selves with merely summarizing the evidence. We can only state, 

 however, that our repeated traverses have left no escape from the 

 conclusion, that during the climax of the Glacial period, the direction 

 of the ice-movement in Shetland, Orkney, and Caithness was from the 

 North Sea and the Moray Firth towards the Atlantic. 



* Quart. Joiiru. Geol. Soc. vol. xxxvi. p. 648. 



