172 Charles Maclaren, Esq., on Grooved and Striated Rocks 



consisting of the whole mass of water, and moving here 

 freely over an open bay 5 miles wide, would have had much 

 more. The west ends of A and B, then, should have been 

 much more deeply grooved than the east ; while, in point of 

 fact, the former are not grooved at all. It is plain, therefore, 

 that the hypothetical wave had no existence. 



On a flat surface of the rock, at I in front of the granite 

 quarry, striae and grooves running E. and W., and beautifully 

 distinct, cover several square yards. The north front of the 

 granite hill presents abundant marks of abrasion, but I saw 

 no grooves, though, doubtless, they once existed there. 



On the edges of the clay-slate, wliicli is quarried for roof- 

 ing, 2 miles east of the ferry, there are large conspicuous 

 grooves running horizontally at an elevation of })robably 40 

 feet above the sea. Some of them seemed to be 5 or 6 inches 

 broad. 



Glen Spean — Arrow 1. — From the Catholic chapel, a short 

 distance eastward of Glen Roy, to the granite hill towards 

 Loch Laggan (represented by an oval, shaded space, on the 

 map) a line of 4 miles, abraded rocks are very numerous : 

 striae were not common, but they were found at four or five 

 places. They were horizontal, and on vertical or inclined 

 surfaces. That the motion of the body which produced them 

 was fi'om east to west, might be inferred from the abrasion 

 being greatest on the eastern sides of the rocks ; but a 

 more direct proof was afforded by the distribution of the 

 granite boulders. These are scattered in thousands over the 

 surface of the mica-slate for a mile westward of the gra- 

 nite hill, and of all sizes, up to blocks weighing ten tons. 

 Smaller masses are found as far west as the bridge of Roy, 

 and beyond it. Granite blocks are also met with on the ter- 

 races of the parallel roads. I counted twelve on two miles 

 of the lower and second terraces, varying in bulk from half a 

 cubic yard to two cubic yards. As they had lost their angles by 

 weathering, speciniens were not easily procured, but I was 

 able to satisfy myself that some of them were identical with 

 the rock eastward, alluded to. Others may belong to the 

 granite mass seven miles northward, at the head of the River 

 Roy. Mr Darwin found granite blocks on the hills between 



