499 



presented, however, a deep section of superBcial matters. First was 

 the compact blue or boulder clay containing small stones. Next 

 was a rouofh brown clay drift, containing large boulders, all rounded, 

 and many of them smoothed and scratched. Over this lay a bed of 

 tolerably pure sand, and over all was a thick deposit of debris from 

 the hill-side, including many large angular masses. The boulders 

 in the clay beds have been reported on as from the rocks of the dis- 

 trict. One which lay in the brown drift just beyond the gorge, to 

 the eastward, was a square mass of arenaceous limestone, probably 

 from a bed in the hill-side little more than a hundred yards to the 

 westward. It was three feet long by twenty inches broad, and was 

 split up by the workmen into six slabs, exposing a multitude of the 

 characteristic conchifers of the formation to which the bed belongs, 

 besides a few vegetable remains, apparently calamites. What was 

 very remarkable, this block bore the glacial dressing with strise on 

 two sides crossing the planes of stratification, and further seemed 

 partially watei'-worn on one of its ends. 



It is important to remark that the boulders were all of eastward 

 transport, and in perfect accordance with this fact was that of the 

 deep section of superficial matters being presented to the eastward 

 of the gorge. A precisely similar deposit being found to the east 

 of the Loch Crag, between Windygowl and Duddingston, we may 

 fairly conclude that the westward side of these prominent masses 

 was the stoss scite or exposed side, and the eastward the lee side, 

 with regard to the movement of the agent by which the attrition 

 was produced. 



The operations for the new road within the garden to the north 

 of Duddingston Church have since laid bare a sloping face of ex- 

 ceedingly hard greenstone, which had been only covered with a thin 

 bed of vegetable soil. I am assured that this face, though not 

 smoothed or marked with strias, was dressed and channeled in much 

 the same manner as the well-known surfaces on the west slope 

 of the Costorphine Hill, which were first described by Sir James 

 Hall. 



It is worthy of notice that the smoothed hollow above Samson's 

 Ribs was 385 feet above the level of the sea. The ice-worn pass 

 at Windygowl is about 1 80 feet above the sea. 



Glacially-marked surfaces have within the last few years been 

 laid bare at three other places in this group of hills. 



