236 ISLA. ALLUVIA. 



they are in no respect interesting. Two crosses of tolerable 

 sculpture in high relief, although of clumsy proportions, 

 are still entire in the enclosures of the chapel at Kildalton, 

 and similar remains are to be found in other parts of the 

 island. I may add to this enumeration, that the ruins 

 of a vitrified fort are to be seen near the northern extremity 

 of Thurot's bay. 



FEW lakes, and fewer swampy spots, are found in Isla; 

 the drainage being tolerably perfect, and the small streams 

 by which it is effected, numerous. These rarely unite to 

 form a larger body of water ; the only two which can 

 at all pretend to the name of rivers, being the Sorn and 

 the Laggan. To this drainage is in a great measure owing 

 its fertility, and the facility with which, on comparison 

 with most of the northern islands, the rough lands are 

 brought into cultivation. Rivers of so little power will 

 not be expected to have produced much change in the 

 surface; nor can we ascribe to them the alluvia which 

 form so conspicuous a feature in this island; since, in 

 most cases, they are far removed from the influence of 

 these streams. The borders of the Laggan indeed are, 

 towards its exit, formed by high banks of clay and gravel 

 reaching even to twenty feet in altitude ; and similar banks 

 are to be traced along the courses of many of the smaller 

 rivers : but a consideration of the general disposition of 

 the great alluvia, will be sufficient to show that these are 

 not the effects of the streams ; which have only ploughed 

 their way through the yielding materials they have tra- 

 versed. The magnitude and depth, as well as the dis- 

 position of the alluvia of this island, form one of its most 

 characteristic features ; being circumstances by which it is 

 strongly distinguished from most of the Western islands. 

 Jura, Scarba, and Lunga, the continuations of the same 

 rock and the same ridge, are free from such deposits. 

 The alluvia in question are to be found in many places, 



