Eev. J. Brodie on Level Terraces. 



343 



have been made on the banks of the Clyde still more de- 

 cidedly confirm this conclusion. In some excavations in 

 the neighbourhood of Glasgow the workmen came on a 

 number of ancient vessels, generally made out of a single 

 tree. They were found at different depths, and when first 

 exposed were quite entire. They had evidently owed their 

 preservation to their having been sunk completely under 

 the water. If they had not been protected from the weather 

 by the sediment in which they were embedded, they would 

 very speedily have rotted away, and left no trace behind. 

 We therefore conclude that the carse lands of Scotland 

 must be regarded as bottoms of the estuaries of a former 

 time, raised, we may presume, some feet above the present 

 high-water mark. In that position they have been sub- 

 jected to the horizontalising effects of the high-water 

 billows. The upper parts have thus received that level 

 surface which they now exhibit. The lower portions are 

 the deposits of more ancient times. The plains of sand, or 

 sandy soil, which we term links, are found on the shores of 

 the open sea. Wherever debris has been thrown up by the 

 tide, and land has been gained from the sea, the ground 

 thus formed has exactly that elevation above the level of 

 the ocean which we would expect to result from the action 

 of the advancing billow. Where the beach is open, the 

 level surface is from 5 to 15 feet above ordinary high-water 

 mark, the height varying according to the force of the 

 wave. In general they are covered by a quantity of drifted 

 sand; their surface is consequently irregular; but after allow- 

 ing for the irregularities thus produced, their elevation is 

 exactly such as we might have expected to find in a high- 

 water terrace produced by the action of the sea at its pre- 

 sent level. We do not find in these links any evidence of 

 an elevation of the land by internal forces ; but that eleva- 

 tion, proved by the discoveries to which we before referred 

 to have occurred, must have tended very largely to increase 

 their extent. The other range of terraces, which are usually 

 described as from 20 to 30 feet above those to which we 

 have been referring, are comparatively of small extent, 

 which suggests the idea of a shorter time having been occu- 



