498 



come from a distance. The phenomena were carefully observed at 

 the time, and reported on to this Society by our associate Mr David 

 Milne (now Mr Milne-Home). 



The formation of a road to Duddingston along the south side of 

 Arthur's Seat has, during the first three months of this year, 

 revealed a set of phenomena precisely similar in character, at the 

 well-known pass of Windygowl, through which it was necessary to 

 make a deep cutting. This pass, it may be remarked, was simply 

 a low point or breach in the crest of an upturned bed of porphyritic 

 greenstone which comes prominently out to the south in the form 

 of what is called the Girnel Crag, and on the other side loses itself 

 in the mass of the hill, the dip being to the north-east. When the 

 surface matter was taken off at this place, a tenacious brown clay 

 was disclosed, very much like that which had formed the covering 

 of the smoothed rocks above Samson's Ribs. When this was 

 removed, the upturned edges of the greenstone bed were laid bare ; 

 basseting of course towards the south-west ; and all were found to 

 be rounded, smoothed, and striated, the strias lying in nearly an 

 east and west direction. The rocky outline formed an irregular 

 hollow, of which about six feet was thus worn, being the portion 

 heretofore covered with clay, while about thirty feet more was com- 

 posed of the rough weather-worn cliffs of the Girnel Crag on the 

 one hand and the hill-side on the other. The only difference 

 between the hollow here laid bare and that formerly exposed at 

 Samson's Ribs, was that the rocks were less worn down. There 

 was not here, as in the other case, a complete trough with smooth 

 sides or walls, and every longitudinal chink worn, as I remember to 

 have observed, down to the bottom, as if by some searching — I might 

 say insinuating — agent. W"e only saw a rude hollow, whose irre- 

 gularities had been partially ground down — -the same work, as it 

 were, half done. There was not, however, a single prominent face 

 of rock within the hollow which did not show more or less of round- 

 ing, smoothing, and streaking. It is worthy of remark that these 

 appearances were not confined to the immediate gorge cut in the 

 Girnel Crag, which was not more than ten yards in extent, but 

 were partially observed on prominent surfaces of the hill-side for 

 fully fifty yards to the westward. 



Immediately to the east of the gorge, the cutting, though descend- 

 ing at a rapid angle towards the lake, did not reach the rock. It 



