76 HARBOUR CONSTRUCTION. 



On the shores of the Bay of Peterhead, at about half-tide 

 level, there are 1 some huge, erratic, water- worn granite boulders, 

 which are not of the characteristic rock of the neighbourhood. 

 The largest of these weighs at least 90 tons. These have been 

 pointed out to me on more than one occasion as evidence of the 

 force of the waves, which must have transported them from 

 nobody knows where, and deposited them where they now lie. 

 Doubtless, at first sight such an impression might easily be 

 formed ; but, as a matter of fact, these huge boulders were trans- 

 ported by glacial action, and the only part which the waves 

 have played in placing them where they now lie has been that 

 of washing away the clay from underneath and around them. 

 In the cuttings of a railway which was formed through this 

 boulder clay, similar boulders were met with at various levels ; 

 and many may also be seen protruding from the clay along the 

 coast, some of which are scored by grooves, evidently caused by 

 glacial action. 



My own impression is that much may be accounted for and 

 many apparent difficulties solved by taking into consideration 

 the movement of the earth's crust (gradual or otherwise), which 

 we know is going on in many parts of the globe at the present 

 time, and to which, in past ages, we attribute many of the 

 mighty changes which a study of geology reveals. 



I had occasion, in constructing the railway before referred to, 

 from the south bay of Peterhead to the admiralty quarries at 

 Stirling Hill, to run a spoil bank of boulder clay into the sea. 

 The action of the waves very soon washed down portions of this 

 clay, and, removing the more solvent portions, formed a beach of 

 boulders, gravel, and sand. The waves sorted these materials, 

 and arranged them generally in alternating layers. 



Throughout the cuttings along this railway, beaches, similar 

 in every detail to the one so formed, occurred at various levels. 

 One was cut through at the level of 50 feet above low water ; 

 another one of large extent at the level of 64 feet ; and others at 

 different levels up to about 175 feet above sea-level. 



There is not the slightest doubt, in my mind, that these now- 

 raised beaches which contain marine shells were, during successive 

 periods, at the sea-level and, in fact, formed the ordinary sea- 

 beach, the levels at which they now lie being the result of gradual 

 upheavals of the land, extending possibly throughout long ages. 

 1 Some of these have been recently broken up aud removeJ. 



