20 6 Dr. Richardson's Letter on the basaltic Surface 
our fa9ades could not have been so formed, for we always 
find them on the highest part of the cliff, and receding from the 
water, which could be instrumental in bringing down the 
materials from above, only by washing, and so wearing away 
the bases of the steepest parts ; but the elevations of these 
bases are utterly irreconcileable to this supposition ; for in- 
stance, the base of Pleskin fa9ade is two hundred feet above 
the present level of the sea, that of Fairhead three hundred ; 
now had the sea ever risen to either height, it would have 
submerged a great part of Ireland, and none of the neigh- 
bouring country (whatever its level may be) bears the least 
resemblance to alluvial ground, nor shews any mark of 
having been once covered by the sea. 
The next argument is still more conclusive ; the boundary 
of our basaltic area on its north side, is for twenty-five miles 
also the confine of sea and land ; so far it is natural to ascribe 
its features, and characteristic marks, to the action of the 
powerful element that beats against it. But when that preci- 
pitous boundary ceases to be the confine of sea and land, 
turns southward towards the interior, and becomes the line 
of demarcation between the basaltic and schistose country on 
the west, it still preserves its former character ; that is, of a 
range or ridge of very high land, steep to the exterior, and 
sometimes cut down vertically into facades, like its northern 
part that lines the shore. 
Thus Magilligan Rock, (four miles inland) is not inferior 
in magnificence to any of our fa9ades on the coast, its per- 
pendicular section is one hundred and seventy feet, and this 
continuous for a mile ; the facades at Bienkraddock are nine 
miles farther inland, and those of Monyneeny thirteen ; while 
