408 Mr Maclaren oti Ancient Beaches near SUrling. 



Abbey Crag, or northward of a line passing from C to B, would be 

 protected by that rock, which would act as a breakwater, and turn aside 

 the current. The course of that current would correspond with the 

 line of the valley of the Forth for ten or twelve miles below Stirling, 

 which is S. 55 E. or SE. by E., and NW. by W. Its principal 

 action would be in the direction indicated by the arrow X. Of 

 course the portions of the terrace northward of a line passing from C 

 to B would be in a great measure screened from its assaults. The 

 portions a h more directly in front of the tide, have not been swept 

 away ; and the reason is, that they have a basis of rock rising many 

 yards above the Carse. 



A current would be maintained through the opening at / north of 

 Abbey Crag ; but from its course in reference to that hill (A), and 

 the declivity of the hill D, which is very steep, its action would be 

 comparatively feeble. Accordingly, though the terrace exists here, 

 its height is a third or a fourth lower than the average, and a hollow 

 has been scooped out in it in an east and west direction, part of which 

 forms the ornamental pond lying southward from g^ and indicated by 

 a black space in the map. I have spoken only of the current of the 

 flowing-tide ; but of course it will be understood that the ebbing-tide 

 would run in the same channels, and act in the same way, though with 

 less energy. There are two rounded masses A, £, on the east side of 

 Abbey Crag, apparently of clay or gravel, which the shelter of the 

 hill had also saved from destruction. 



Besides the hollow containing the pond, there are two deviations 

 from the usual form of the terrace here, which demand attention. 

 The one is a small specimen of a lower terrace, extending from d 

 to e in the map, and from 30 to 40 foet above the Carse. This 

 terrace (which is distinguished by horizontal shading lines) com- 

 mences at Lord Abercromby's south gate, is about a furlong in 

 breadth, and somewhat more in length, and terminates at the village 

 of Causeyhead, C. It is level and regular in its surface (t" section 3) 

 and has a well marked sea c?iy behind it at k as sharply cut as if it 

 had only recently escaped from the action of the tides. The outer 

 marjrin of the terrace close to the road is about 30 feet above the 

 Carse, the inner margin at the foot of the cliff k,\s 10 or 12 feet 

 higher, that is about 67 feet above the sea. As the tide which 

 formed it must have reached to this inner margin, it may be described 

 as the " II fathom terrace." 



Every part of the cliff k which I examined was of gravel or sand, 

 and I was informed by one of Lord Abercromby's labourers, that the 

 whole was of the same materials. It rises with a steep and sharp 

 acclivity facing the south, to the height of 90 feet above the lower 

 terrace, 30 above the higher, and 155 above the high-water level 

 at Cambuskenneth, according to my rough measurements. From its 

 summit it slopes 'very gently northward till it reaches the pond. 

 The form of the surface will be understood from section 3, where D 

 is the steep flank of Demy at ; t' the higher tcrpce on which Airthrey 



