OP THE FAROE ISLANDS. 255 



cinnstance respecting them is, that they are all coated with an- 

 arrangement of small prisms, set at right angles to their axis ; 

 so that when soine of these nide masses are broken in their 

 longitudinal direction, a circumstance which occurred not un- 

 frequently, a double set of small prisms appeared, to separate 

 the columns, not unlike little dykes ; and when an horizontal 

 direction chanced to be displayed, a radiating arrangement of 

 prisms was observed around the edge. The substance which 

 generally occurs, of a brick-red colour, and forms partial sepa- 

 rations between some of the varieties of trap, seldom extends 

 to any great length ; in thickness it is veiy irregular ; the great- 

 est depth we met of it, was in the vicinity of Kirkeboe in Stro- 

 moe, where it may be from eight to ten feet. It is not 

 invariably of a red colour: under the greenstone at Leynum, it 

 occurs of a dark-green. This material, which in some cases 

 may very readily be mistaken for sandstone, paiticularly as it 

 frequently presents a slaty texture, after being acted on by the 

 weather, appears to me to form a portion of the overlying trap^ 

 although it no doubt presents a very different character. In 

 other beds^ of greenstone, nearer home, alterations equally re-^ 

 markable may be pointed out ; and as we frequently observed 

 in it cavities lined with zeolite, similar to those which were 

 dispersed through the other parts of the same bed, it cannot 

 possibly be considered of a separate formation. 



Notwithstanding the uniformity that prevails in the general 

 disposition of the trap in Faroe, there are some beds which de- 

 part entirely from it. The most remarkable of these, we met 

 with in the vicinity of Norderdahl in Stromoe. A little north 

 of this place, there is a conical hill, presenting a projecting 

 rounded front towards the shore; and being denuded from top 

 to bottom, the structure is distinctly seen, and the horizontal 

 beds traced with the utmost precision. Resting on these, and 



covering 



