OF THE EARTH'S SURFACE. 187 



stream are distinctly marked, and agree with those already ob- 

 served. 



The ridge of the hill is about a mile and a half in length, 

 and rises in the middle to a height, according to the map, of 

 four hundred and seventy feet from the sea, perhaps three hun- 

 dred from its base. Along the summit, which is everywhere 

 planted, the rock is seen bare very frequently, in the midst of 

 the young woods, and often shews itself also in the ad- 

 joining fields. Among these rocks, which I have examined 

 again and again with care, so many examples occur, similar to 

 those just described in Barnton Park, that the hill itself may 

 be looked upon as one specimen illustrative of this import- 

 ant truth, in so far as the great features are concerned. In 

 the following ten specimens, chosen on that same ground, the 

 minuter indications of abrasion are also visible. 



No. 5. In a place called Craighouse, upon the south side of 

 the Queensferry Road, opposite to Barnton Park, and between 

 it and the main hill, a mass of whinstone occurs, making part 

 of the same longitudinal line. It was formerly worked as a 

 quarry, for the purpose of paving and road-making, and is 

 now clothed with young wood. In its highest point it ex- 

 hibits all the large features of diluvian action, but none of 

 the small ones. These, however, it appears, have been de- 

 faced by the action of the weather; for, on removing the 

 young wood and soil from a surface of about twenty yards by 

 thirty of the lower part immediately adjoining, I have disco- 

 vered them in full perfection. Not only the grooves and 

 scoopings make their appearance, but the surface is seen, when 

 drenched with water, to be entirely covered with longitudinal 

 dressings, as already described, in speaking of the specimens 

 on sandstone. Where a rent has occurred at all in the direc- 

 tion of the current, it has guided the formation of a groove, 



A a 2 the 



