406 Mr Maclaren on Ancient Beaches near Stirling, 



avoid circumlocution. In common with nearly all living geologists, 

 I hold that the change of level is solely in the land — that the sub- 

 sidence of the sea is merely apparent, and is the effect of a real rise 

 in the land ; and vice versa ^ that an apparent rise of the sea is the 

 effect of a subsidence of the land. 



An elevation like h' is seen at several parts of the terrace, near 

 the foot of the steep acclivity R, but not everywhere. It may be a 

 storm beach, or bank of shingle thrown up in a storm; or it may have 

 been produced in some cases by torrents from the hill R, sweeping 

 away the portion of sand and gravel nearest the strand. It is enough 

 that such banks are found within the high water mark on the shores 

 of the present sea. 



The evidence furnished by these details, to shew that the terrace 

 was an ancient beach, may be thus summed up : 1. It is composed 

 of such water-worn materials as compose our present beaches. 2. These 

 materials are arranged as we find them in our present beaches ; that 

 is, they are disposed in beds or layers, approximating to a horizontal 

 position. 3. The upper surface of the unbroken parts of the terrace, 

 approximates to a dead level, as in our present beaches. 4. Like these 

 beaches, it meets the hill behind it abruptly ; and it is, as nearly as 

 the eye can judge, parallel to the surface of the Carse, which we know 

 to have once formed the bottom of the sea. 



Now water is the only agent which could have arranged the ma- 

 terials of the terrace, and levelled its surface, as we find them ; and 

 the water must either have been that of the sea or a lake. But the 

 oyster, cockle, and mussel shells found in the Carse westward from 

 Stirling, assure us that the sea once covered it ; and with this evi- 

 dence before us, it would be unphilosophical to explain the facts by 

 assuming the existence of a lake. 



The Airthrey whale, found in the Carse near Blair Logic, 22 feet 

 above the present high-water level, shews that the sea once stood 

 much higher than it now does. In the New Statistical Account of the 

 parish of Drymen, we are told that the surface of the Carse there is 

 nearly 40 feet above the sea. The fact is probably known from Mr 

 Smeaton's survey ; and, assuming it to be correct, the tides which 

 covered the carse must have flowed to that height at least. Again, 

 we have a bed of oyster-shells at the mouth of the river Avon in 

 Linlithgowshire about 37 feet above the present strand ; and as the 

 oyster inhabits deep water, we must add 20 feet for the tide. We 

 are thus furnished with evidence, that in a part of the Frith about 

 15 miles from Stirling, the sea stood at one time 57 feet at least above 

 its present level. It may have been twice as much, for the oyster is 

 known to live sometimes at the depth of one hundred feet. 



If sea-shells had been found in it, the evidence of the terrace being 

 an ancient beach would have been complete. But shells, though not 

 observed hitherto, may yet be discovered in it; and even, if none 

 should be found, it does not follow that they never existed. Shells, 



