852 



THE BRITISH ISLES. 



find ourselves in front of a " pillar'd vestibule " leading into a cavern, whose 

 fretted vault is supported by columns of basalt. When the sea is tranquil, the 

 billows, rolling over the lower pillars, urge their way up the receding sides of 

 this great temple. The murmuring, moaning noises produced by succeeding 

 sura-es in regular cadence account for the Gaelic name of the cave, which is 

 Llaimh Binse, or " Cave of Music." But when the sea is lushed into fury the 

 gentle music becomes a terrible turmoil, and the compressed air, rushing from the 

 cave, produces a sound like thunder, which can be heard several miles off, on 

 the island of Mull. 



The rocks of Dubh Artach form the south-western extremity of the archipelago, 

 of which Mull is the chief member. They, as well as the Skerryvore — or rather 



Fig. 176. — The Head of Loch Fyne. 

 Scale 1 : 20,000. 



'Twr^ 



56;' 



15 



.?e"-ira.\' :' 



I V 



) 



r 



-^...s 



4-55- W.of G. 



Miles. 



Sgir More; that is, "Great Rocks" — rising upon a submarine plateau stretching 

 away from the gneissic islands of CjII and Tiree, arc pointed out from afar by a 

 lofty lighthouse. The Tower of Skerryvore is a rival to the famous lighthouses 

 of Eddystone and Bell Hock, and the difficulties over which its engineer, Alan 

 Stevenson, has triumphed were, perhaps, even greater than in the case of the 

 other two, as the power of the waves in these seas is sufficient to lift a block of 

 stone weighing 42 tons. 



To the south of the Firth of L^rne there extends another chain of islands, 

 formed, like the neighbouring coast, of Silurian rocks. This chain includes 



