US On the lasaltic Surface of the Counties 



We see now what a diminutive portion of our vast basal- 

 tic mass has, until lately, monopolized the attention of the 

 curious; and even after it was discovered that we had many 

 other, and much finer collections of pillars on the same pro- 

 montory, it never occurred to those who were preparing to 

 give accounts of them to the public, to examine whether 

 these were mere desultory groups, or detached parts of a 

 grand and regular whole, which a more comprehensive view 

 of the subject would soon have laid open to them. 



Tenth Stratum, (a). 



The stratum upon which the pillars of the preceding rest, 

 is ochreous, red as minium, and about twenty feet thick ; it 

 is scarcely seen at Portmoon, a patch alone of its surface 

 being distinguishable under water at low tide ; but imme- 

 diately to the northward it shows itself, and from its bright 

 colour, makes a conspicuous figure across the fa.ee of the 

 precipice in a course of more than a mile and half; its last 

 appearance to the westward is at Rovlnvalley , the opposite 

 point of the bay from the Giant's Causeway, from which 

 we have a good view of it. The final dip and immersion of 

 this tenth stratum, as well as its emersion, are lost for want 

 of perpendicularity. 



The six remaining strata are all similar in material, but 

 differing much from each other in thickness ; they are all of 

 that description called tabular basalt, sometimes showing a 

 faint disposition to assume a columnar form at their edges, 

 and alwavs separated from each other by o?hreous layers. 



These six strata are not so perfectly distinct as those above 

 them, for sometimes we think we can count seven, and 

 again not more than five ; nor does each of these preserve 

 the same thickness through their whole extent, for they are 

 deeper towards the northern point, where they culminate, 

 forming by themselves a perpendicular facade near two hun- 

 dred feet high, but they grow thinner as they recede from- 

 this centre. 



The. jets of black rock in the view of Portmnon, are the 

 emersions of these strata ; their last appearance on the west 

 side is at Rovinvalley, where they strongly display the incli- 

 nation 



