560 MULL. GEOLOGY. 



easy to estimate the proportion of the cliffs which it 

 forms, as, when sufficiently near to distinguish between 

 the limestone and the trap, the foreshortening of the 

 height prevents a correct judgment on this point; and 

 when at a proper distance for this purpose, it is not 

 always possible to discriminate between the two. I need 

 scarcely say that these cliffs are utterly inaccessible, and 

 that they are invisible from the land above. But as 

 far as a judgment can be formed, nearly the whole cliff 

 is limestone, the trap which surmounts it in this part 

 of the coast and forms the high hills of the interior 

 country, terminating by a comparatively thin edge at the 

 top of the vertical face. There is no reason to suppose that 

 any considerable sandstone strata lie above the limestone 

 throughout this space ; because no fragments of the former 

 are found upon the shore below, and because where those 

 strata actually occur, they are distinguishable from the 

 limestone at a distance. The height of these cliffs being 

 considerable, the mass of limestone is consequently of 

 great thickness, varying from 200 to 400 feet, as the preci- 

 pitous face gradually rises from Loch Speliv to Loch 

 Buy. The strata enter for a certain space within the 

 mouth of that bay and then disappear among the trap. 

 On its western side they reappear at a corresponding 

 point and at the same altitude, continuing for more than 

 a mile along the southern shore, and, as before, occupying 

 nearly the whole thickness of the cliff from the sea to 

 the surface. At this point however the body of strata 

 quits the shore, but is still continued without any sensible 

 alteration of its dimensions as far as Carsaig. It thus 

 lies between two masses of trap ; that rock skirting the 

 shore to a certain elevation as far as Carsaig, and also 

 surmounting the strata as in the eastern part of the coast. 

 Here the limestone appears to terminate, but it will imme- 

 diately be seen that the strata of sandstone usually associated 

 with it are continued in the same manner, and without 

 discontinuity, to the western cliffs of Inimore. There are 



