210 D. Milne Home — Gkiciation of the Shetlands. 



(2). HaYing thus shown that the direction of the slrm does not 

 favour the advent of this great mer de glace from the N.E., nor its 

 course across the isLands to the N.W., let me notice shortly the 

 statements in the paper, that the Erratics and Drift in the Islands 

 confirm that theory. 



As regards Unst, — where Messrs. Peach and Home say the carry 

 of the Boulders was across the island from the East to the West 

 Coast, — the facts stated by Mr. Peach, senior, and not affirmed to be 

 incorrect, are distinctly against that view. 



A similar discordance exists in the Island of Bressay, which is 

 also on the Eastern Seaboard. On it Messrs. Peach and Home 

 allow they found erratics which had come from the N.W. — brought, 

 as they suggest, by the local glaciers of the Mainland ; — of which 

 glaciers, however, I respectfully repeat that I see no evidence given 

 in the paper. 



Therefore, neither at Unst nor at Bressay is the direction of the 

 drift in accordance with Messrs. Peach and Home's theory, which 

 requires a movement from the eastwards. 



Then, when the position of the Boulders found on the Western 

 Seaboards is examined, they certainly do not show transport from 

 the S.E. — which is stated to have been there the movement of 

 the mer de glace across the islands. Messrs. Peach and Home say 

 that the " occurrence of these Boulders in the drifts on the West 

 Coast, and as erratics on the hill tops, is due to the same cause, viz. 

 to the westerly movement of the gi'eat mer de glace, which was 

 powerful enough to over-ride the watershed" (p. 804). 



The authors of the paper, though they refer in a footnote to 

 " Hibbert's admirable volume on the Shetland Islands," curiously 

 enough, omit notice of the Boulders which he observed on the 

 Western Seaboards, and of the opinion he expressed as to the 

 quarter from which they came. Thus, he says (Edin, Journ. of 

 Science for 1831, vol. iv. p. 86), that in the "small Island of Papa 

 Stour," composed of sandstone and secondary porphyry, "numerous 

 fragments are found, even in the interior of the island, of a peculiar 

 and very beautiful hornblende schist and actinolite schist, which is 

 nowhere to be met with in this Archipelago, except at Hilswick 

 Ness — a distance, when measured across the Bay of St. Magnus, of 

 at least 12 miles. I also found that, besides these fragments, relics 

 of other distant primary rocks were strewed about, less easily, 

 however, to be identified than those which I have described." 

 Dr. Hibbert adds, that if he is correct in believing that these 

 schist blocks came across St. Magnus Bay from Hilswick, the agent 

 which transported them moved from N. 47° E., a dii-ection at right 

 angles to the direction of the alleged Scandinavian Ice-sheet. 



It appears that this same Island of Papa Stour was visited by 

 Professor Geikie ; and he too was struck with the number on it of 

 "transported blocks of gneiss, schist, and other rocks foreign to 

 the locality," thus confirming Dr. Hibbert's testimony as to the 

 occurrence of Boulders there, transported from some distant point ; 

 — though he does not indicate the quarter from which they had 



