286 Mr Maclaren's Betnarks on Natural Terraces 



stream, and laid down on their lower sides, so as to give these 

 peninsulas a very slow progressive motion towards the sea. 

 The whole surface between the high lands on the two sides, 

 having been repeatedly subjected to this levelling process in 

 the lapse of ages, acquires the appearance of a stripe of flat 

 meadow-land, the height of which may be accidentally raised 

 from time to time by the new matter deposited during extraor- 

 dinary floods. It is possible that the lowest terrace at Perth — 

 I mean the Inch — may be of this description. 



I saw no terraces on the sides of Loch Tay, except towards 

 its west end. Near the road about two miles north of Killin, 

 I saw what I considered a terrace, though not very well 

 marked, which, measured by the sympiesometer, I found to 

 be about 240 feet above the loch ; and it will probably be 

 about 650 feet above the sea. Traces of others were observ- 

 able at higher elevations, but rather equivocal. They con- 

 sisted of small areas of sandy soil, nearly level, with small 

 raised banks, partly of earth, partly of rock, behind them. 



An ancient beach, from six to twenty feet above high-water 

 level, with a water-worn sea-cliff behind it, is seen on the 

 shores of the Clyde, at Greenock, Gourock, and other places. 

 It is beautifully exposed in Rothsay Bay, and round to Ascog, 

 and is conspicuous on the east coast of Arran. 



The soil on all the highland mountains which I visited, 

 from Dunkeld to Inveraray, was of sand like sea-sand, with a 

 small mixture of rolled stones. This is in all probability the 

 same deposit with the third or highest alluvium of the Lo- 

 thians. There are deep beds of the same substance in the 

 valleys, with huge fragments of rocks mixed with them, or 

 resting on their surface. Some of these fragments measure 

 three or four yards each way, and must weigh 50 tons or 

 more. They are generally angular, and belong to the rocks 

 in the neighbourhood. They may be considered, I think, as 

 representing the second alluvium of the Lothians, or the clay 

 with angular stones. Of our lowest alluvium or stifle blue clay 

 with rolled stones, I did not observe a vestige ; and I saw the 

 superficial deposits in contact with the rock in so many in* 

 stances, that if it had existed in the mountainous tract be- 



