322 W. T. Black — Grooved Boulders, Edinburgh. 



The dimensions of the smaller trap Boulder (No. 1), in the north 

 area, were 1ft. high, 1ft. 9in. long, the horizontal circumference 

 was 5ft, 6in., and the depth of the platform 5ft. from the surface. 



Both of these Boulders were grooved all over their upper surface, 

 and the markings were all in one direction, except one or two streaks 

 might be somewhat diagonally placed with respect to the others. 

 The depth of the grooves was about |- to |^ of an inch, and the 

 breadth ;^ to -^ an inch or more, and they extended right across the 

 planes they scored, some being as long as 12 inches, and some as 

 short as 2 inches. 



Many of the grooves started abruptly into the surface of the 

 boulder, whence they gradually shaded off to streaks, which some of 

 them began with and ended, while the middle was deeply cut. 



The Boulder (No. 3), without grooves, lying in the eastern cutting 

 on the north area, was of the usual trappean description, with 

 rounded edges and comers, and laminae on the surface, that peeled off 

 in superficial cakes. 



Its dimensions were : 1ft. 4in. deep, 1ft. 9in. broad at the larger 

 end, 2ft. 9in. long, with a horizontal circumference of 7ft. 5in., and 

 it lay loose on the platform. 



A flat Boulder (No. 4), of buff-coloured sandstone, in the north 

 area, lay loose on the surface, and had its upper surface scored with 

 deep grooves more or less parallel. 



In the southern area of the hospital grounds were found, exposed 

 in the excavations, about a dozen other Boulders, all of trappean 

 character except No. 7, which was of a violet-coloured crystalline 

 sandstone. Of these, eight were found scored with grooves of 

 a similar character as those described on the boulders in the north 

 area, and the sandstone block, No. 7, was also well marked with 

 streaks. 



The dimensions of one in the west cutting (No. 10) were : 1ft. 

 high, 1ft. 7in. long, 1ft. Sin. broad, and it was 5ft. Gin. in circum- 

 ference, oval in shape, and had grooves on two sides, all in the 

 same direction, and the depth of the platform was about 2ft. 



In the middle cutting was a large rounded one (No. 11), in situ, 

 in the bank and near the surface of the soil, when the upper surface 

 had only grooves, and these, like the last, tended all down hill. 



Its dimensions were : length, 2ft. Sin. ; height, 1ft. 4in. ; and 

 depth of platform, 2ft. ; so that the soil above it was 8 in. deep, and 

 of this half was of loam and the rest the marly subsoil. 



None of the above-mentioned Boulders were seen to lie on the 

 subjacent rock, but were all lying in the middle or near the top of 

 the clayey stratum. 



The rocky bed below this has only been exposed in one place in 

 the south area, at about six feet below the surface, and this is a buff- 

 coloured soft sandstone superficially, but of more densely crystalline 

 structure deeper. 



These igneous Boulders can be conjectured to have been carried 

 by glacial or aqueous agency from numerous sources in the neigh- 

 bourhood of Edinburgh ; as the Castle Hill to the north, Corstorphine 



