136 Charles Maclaren, Esq., on the Existence of 



Y Loch Goyle. 



D Loch Lomond 



F The Firth of Clyde. 



A The peninsula of Roseneath, consisting of hills from 

 300 to 600 feet in height. 



B The hills on the east side of Gareloch, from 600 to 800 

 feet in height. 



C A more elevated ridge, probably 1600 or 1800 feet in 

 height. 



D Another ridge still a little higher. 



M K I H E, a series of lofty mountains skirting the west 

 side of Loch Long, surrounding Loch Goyle, passing round the 

 north end of Loch Long and Loch Lomond, and terminating 

 in Ben Lomond (E). Few of the summits are under 3000 feet 

 in elevation, and several are considerably higher. The whole 

 form a mountain barrier, remarkable for rugged grandeur, 

 which encloses the peninsula, A B C D, on the west, north, 

 and north-east sides. The lowest portion is a ridge at I, 

 forming part of what is called Argyle's Bowling Green. By 

 taking the vertical angle, and measuring the distance on the 

 map, I found its height to be about 1300 feet. But behind 

 it there are hills considerably higher. The peninsula being 

 thus fenced round on three sides by a rampart of mountains, 

 the question meets us, Whence did the granite boulders at Gare 

 Loch come, and how were they transported ? 



I found about thirty blocks of granite, of 2 feet or more in 

 breadth, on the beach, or within a mile of the loch, and many 

 more of smaller dimensions. The largest I saw was 5 feet 

 in diameter, and must have weighed nearly six tons. They 

 were all of grey granite, and much rounded, especially the 

 small ones, some of which were perfect globes. Most of the 

 large blocks were porphyritic, containing disseminated cryS' 

 tals of felspar, of a pale pink colour, half an inch or more in 

 breadth, and an inch and a half or more in length. I found 

 them at various elevations ; the highest, about a cubic yard 

 in bulk, was perched on the top of a hillock a quarter of a 

 mile east from a, and at an elevation of 320 feet above the 

 loch. 



The localities in which granite is found nearest to Gare- 



