74 GEOLOGY OF ARRAN. 



they might have been hurled headlong from the summit to 

 the sea-level. Other causes must be sought for the transport 

 of this enormous mass from the parent mountains ; and of 

 others still farther removed, though of lesser magnitude. We 

 have already considered the only possible causes, and at- 

 tempted, to estimate the evidence in favour of each (Arts. 20, 



Fig. 16. 



22). That to which we chiefly lean receives support from 

 the case before us. A crowd of lesser blocks- surrounds the 

 huge boulder of which we speak an association much more 

 likely to occur in the case of glaciers or bergs than of currents 

 emanating from a centre so remote. The cubical contents, 

 and consequently the weight, are very difficult to estimate on 

 account of the irregular form. The dimensions at the base 

 are 21 feet by 12, and the height 15 feet. If rectangular, it 

 would weigh 315 tons ; but if we deduct one-third for the 

 conical form, which is a large allowance, we shall have a 

 weight of 210 tons. 



The cliff we have had on our right all along subsides here, 

 and the cultivated fields of the Dun-an and Corriegills farms 

 come down to the water's edge. The northern mountains are 



