On (he Shelves of LochaOer. 11 



courses which the water must have taken through the valleys, 

 and from the eddies caused by the meetings of currents. 

 Wherever glens may exist having the same peculiarities, in 

 reference to the direction of the great flood, there we may 

 expect to find similar shelves. Partial appearances of shelves 

 may be seen here and there, which may not exactly accord 

 with the circumstances of those in Lochaber. But when we 

 contemplate the operations of such a flood as has been 

 supposed, and consider that its movements over the uneven 

 surface, and through the sinuosities of the land, must have 

 subjected it, and the materials carried along by it, to very 

 variable conditions, we may reasonably expect to find effects 

 which cannot instantly be accounted for. Many of the ter- 

 races we find in valleys have been formed in a manner differ- 

 ent from the operation of waves throwing materials against 

 a slope. Tt appears in many places that the gravel, sand, and 

 boulders have been deposited in the valleys so as to leave a flat 

 surface. As the waters subsided and formed powerful streams, 

 this flat surface has been cut through, and much of what had 

 been deposited carried away, leaving fiats, more or less ex- 

 tensive, with faces sloping towards the streams. 



Another probable result of the passage of the flood may be 

 considered, in reference to those portions of the island 

 towards the eastern coast, which are open and comparative- 

 ly free of mountainous elevations. In such localities the 

 waters must have spread out, still, however, flowing and ed- 

 dying in its general direction, and retaining its general level. 

 Of this level, in its variations in elevation, whei*ever we may 

 suppose the water to have been more quiet, (as it must have 

 been in the Lochaber glens) we may expect to find traces. 

 If in the North Iliglilands and elsewhere there be spaces over 

 which tlie waters could spread, and be less agitated ; or 

 glens, such as those of Lochaber. or others in which they were 

 confined, their general level and its traces would be the 

 same in all similar localities, though distant from each other, 



I have only fartlier to observe, in reference to the attempt- 

 ed assimilation of the shelves and terraces we have been con- 

 sidering to sea-beaches, by Mr Darwin and others, that the 

 materials composing the ft;rnicr are the same with those 

 composing the genei'al diluvium or drift; whereas existing 



