1823.] the principal Mountain Chains of Europe. 5 



(B .) Scotland— Ireland— England. 



The chains traversing the Shetland isles and the Scotch high- 

 lands and Hebribes, maybe, perhaps, regarded as continuations 

 of the Scandinavian range. •.'.«. 



Mica slate is here the predominant rock: granite, however, 

 forms the nucleus of several mountains The phenomena exhi- 

 bited by the junctions of the granite and the veins sent off by it 

 i, to thi incumbent rocks, have been here minutely studied, and 

 accurately described. The only writers who have yet given 

 precTse accounts of this district (Drs Mac Culloch and Bone), 

 concur in favouring the hypothesis which ascribes to the granite 



^veT narifw'zone of transition slate separates this chain 

 from the great central valley of Scotland occupied by the carbo- 



111 ThT highland chains of mica slate after expiring against the 

 Irish channel in the peninsula of Kutire, appear to be resumed 

 on the opposite side in the north-east angle of Antrim ; and 

 thouo-h concealed for an interval by the overlying rocks of the 

 basaltic area re-emerge beyond them in the west of Derry and 

 oc u, V near y the whole of Donegal the structure of these 

 countries exactly corresponding with that of the Scotch high- 

 lands Donegaf Bay for a time interrupts the continuity of the 

 chain • bit beyond that Bay, the primitive mountains of Slip, 

 Mayo,' and Connemara, or Vestern Galway, must be regarded 



"A^coKSn of mountains parallel to the former traverses 

 the south of Scotland skirting on that side the great carboniferous 

 valley, and forming the natural boundary between this country 

 and L Enoland. It is known by the name of the ead hills in its 

 cent, Ta and highest part; the Pentlands, fce. forming branches of 

 lt It consist's principally of transition slate, through which gra- 

 nitic nuclei emerge in several groupes; and may be characterised 

 from the northern chain by the absence of mica slate. 



This chain also may be traced in its prolongation on the oppo- 

 site coast of the Irish channel ; its abrupted ends appearing on 

 each side of the usual passage across that channel from Portpa 

 trick to Donaghadee. In Ireland it extends from Down into 

 Longford retaining the characters already mentioned; the 

 ^Mountains! a granitic nucleus, here constitute its prin- 



^Tt^h^n chains of Ireland may be more conveniently 



^^^^^oZ^^i^ the lakes of West- 



• I desire to be here conned mg^ffg^^^jS^SSi 

 tA\&ZS£S> aSKT&tBS aU can hardly record £2 

 evidence without feeling myself convinced by it. 



