160 Proceedings of the Royal Physical Society. 



the agent was evidently the same as that which grooved and 

 polished the rocks beneath. . . . All of them I have yet 

 observed have their direction and striation E.KE. — the general 

 direction in the district of the lines and grooves below; 

 almost all of them decline slightly to the east, and, when 

 relieved by the waves, resemble low flat moles stretching 

 from the land into the sea. They indicate, I am inclined to 

 hold, pauses in the formation of the boulder-clay deposit, 

 during which its general surface was lowered and came to be 

 thickly covered with the disengaged pebbles and boulders of 

 the general mass, ranged in one place. And then the old 

 agency recommenced its operations, and pressing the stones 

 down into the mass, so as to imprint, the pavement-like re- 

 gularity on their surface, it grooved and striated them, as 

 when acting at an earlier period on the rock below. These 

 curious pavements may be regarded as conclusive in the 

 proof they furnish that the boulder-clay was not, as some 

 think, a simultaneously formed deposit — the produce of some 

 great mud- wave from the sea — but of slow formation ; and, 

 further, that it presented surface after surface to the great 

 grooving and polishing agent to which it seems to have owed 

 its origin." ^ This agent he believed to have been icebergs. 



These remarkable houlder -pavements (as my father terms 

 them in an MS. reference) were pointed out by him to 

 Eobert Chambers, who also described them. ^ His descrip- 

 tion of the "narrow trains of blocks crossing the line of 

 beach . . . not more than a foot above the general 

 level" is virtually the same as that just quoted. "There are 

 also," he adds, " some appearances of a hollow on the surfaces 

 of these curious pavements, as Mr Miller calls them, as if 

 some enormous wheel had run along the surface in that 

 direction, and left on it a slight track ; " and he concludes 

 that here is " a surface of the boulder-clay deep down in the 

 entire bed, which to all appearance has been precisely in the 

 same circumstances as the fast rock-surface had previously 

 been." 



1 Lecture on the Geological Features of Edinburgh. Reprinted in " Edin- 

 burgh and its Neighbourhood," pp. 38-40. 

 ' Edinr. Phil. Jour., vol. liv. (1852-53). 



