186 ON THE REVOLUTIONS 



No. 3. The third is within the court of the old farm yard of 

 Ravelstone. The greatest part of this court consists of a rock 

 entirely bare, and nearly horizontal ; the whole surface of 

 which exhibits the dressings in the most distinct manner, be- 

 ing entirely composed of furrows, some of which are of a large 

 size. 



No. 4. The fourth specimen occurs near the foot of Corstor- 

 phine Hill, upon an old quarry, called the Well Craig, within 

 two or three hundred paces, bearing east 25° south of the 

 old castle of Craigcrook. It presents the dressing very di- 

 stinctly, and, like the two first specimens, upon a rock sloping 

 rapidly to the south. 



These specimens are all upon sandstone. The remaining 

 cases belong to whinstone, which, as has been said, occupies 

 the upper part of Corstorphine Hill, sloping to the west The 

 ridge of the hill lies north and south, with an inclination of 

 about twenty degrees west of north. It therefore meets our 

 supposed westerly stream nearly at right angles. The ridge, 

 as seen from Edinburgh, is very much serrated, being cut 

 across by small ravines ; and upon the north, after the ge- 

 neral mass has sunk below the neighbouring country, the 

 whinstone makes its appearance in various elevated masses in 

 Barnton Park, lying in the prolongation to the northward of 

 the longitudinal line ; the most northerly of these elevations, 

 which comes within forty or fifty yards of the old house of 

 Barnton, rising not more than six or eight feet above the turf. 

 These rocks, all of which, like the hill itself, present a slo- 

 ping face to the west, exhibit, upon that face, all the large di- 

 luvian features already described : the rotundity, together with 

 the grooves and scoopings ; but none of the scratches, or other 

 small features, are to be seen. The character, however, of the 

 general operation is so well shewn, that the bearings of the 



stream 



