RAVINES-GORGES. 83 



In the three Lothians, we might cite innumerable examples 

 of gorges and ravines, which, though traversed by streams, 

 still, from the great disproportion which exists in their re- 

 lative magnitudes, have evidently been produced by agents 

 in no way connected with the water which flows through 

 them. To form these valleys by water, some geologists 

 may only demand a great lapse of time ; but others, from 

 considering their various appearances, and remembering 

 that, if a given cause is inadequate to produce a given ef- 

 fect, the endless operation of that cause avails nothing, will 

 only refer them to great and instantaneous convulsions. 



The high vertical faces of the rocks, in every instance, 

 exhibit evident proofs of fracture, and present no appear- 

 ances which can reasonably be considered as produced 

 by the long-continued action of a stream. Though alte- 

 rations in the position of strata, are, in the generality of 

 cases, to be referred to the presence of unstratified rocks, 

 still many of the rents which we are noticing, seem, from 

 crossing strata which are in a horizontal position, and, in 

 many instances, far removed from igneous masses, to be re- 

 ferable to other Plutonic actions than those which have pro- 

 truded the augitic and felspathic series. On the nature of 

 these we have no intention to speculate at length. May 

 they not, however, be traced to the actions which raised the 

 countries we are noticing above the waters of an ancient 

 ocean ? As some localities where fissures appear to traverse 

 the strata, we may mention the Heriot, Dunglass, and Pease 

 burns, the glen of Pockbie near Soutra Hill, and nume- 

 rous points in the courses of the rivers Almond, Leith, 

 Gladhouse, and North Esk. 



The slate which is seen in an upraised position at Hab- 

 bie's How, is to be met with in other parts of the Pentlands : 

 near Be vela w House, it occurs in vertical strata, ranging 

 f2 



