156 David Milne, Esq., on Polished and Striated Rocks. 



the spot may be visited by thousands of persons, without more trouble 

 than is required for a pleasant half-hour's walk ; whereas most of 

 the places where similar phenomena have been previously observed 

 are remote and inaccessible, in which case credit must be reposed on 

 the accurate perception and description of a single or few observers. 

 In the second place, the nature of the locality is such, as to preclude 

 the applicability of some of the hypotheses which have in other cases 

 been admissible for explanation. 



For these reasons, it occurred to me as desirable to make known 

 and record the appearances presented at Sampson's Ribs, bearing as 

 they do so materially on those curious speculations regarding revo- 

 lutions on the earth's surface, which are supposed to have occurred at 

 a comparatively recent period. I expressed a wish that others more 

 competent, and with better [opportunities of observation, would under- 

 take this duty, but without success. 



I. The spot where the rocks in question occur, is in a small hollow 

 between the main body of Arthur Seat, and that outlying portion of 

 it which has received the name of Sampson's Kibs, from its beautiful 

 basaltic columns. These columns form part of a hummock or knoll, 

 which is separated from Arthur Seat by a hollow or gully opening 

 out freely at each end, — towards Duddingston Loch at its SE. end, 

 towards Edinburgh at its NW. end. 



Through this hollow or gully the new road passes ; and the level 

 of the road is 27 feet below the top of Sampson's Ribs, from which it 

 is distant probably about 100 yards. Rock has been found at differ- 

 ent parts on each side of the road ; and there the rocks on each side 

 are converging downwards towards each other, as if to meet under or 

 below the road, and where they probably do meet at from 10 to 20 

 feet below its level. They form here, therefore, a trough, one side 

 of which is the base of Arthur Seat, and the other, the knoll of 

 Sampson's Ribs. 



The width of this trough or gully, L e., the distance between the 

 rocks on each side of it, is (at the level of the road) about 30 feet ; 

 and (about 6 feet higher up) about 38 or 40 feet. At the level of 

 the top of Sampson's Ribs the width, or, in other words, the distance 

 to Arthur Seat is about 140 feet. 



The gorge or gully now described runs about NW. and SE. by 

 compass. The top of Arthur Seat, if it could be seen (for the sides 

 of the hill, which rise up almost vertically from this trough, conceal 

 the view of it), would bear about east by compass. The top of 

 Sampson's Ribs is about 420 feet below the top of Arthur Seat, 

 and about 200 feet above the average surface of the low level country 

 which extends from the foot of Sampson's Ribs southward and east- 

 ward for some miles. The gully itself is about 380 feet above the 

 sea. 



It is farther proper to observe, that the gully in question, which 



