194 On the basaltic Surface of the Counties 



fled. I cannot, however, conclude without one more ob- 

 servation : — During the ebb tide, }f the shore is rocky, a 

 number of small pools of clear water are left, in which will 

 be found many of the smaller plants adhering to the stones 

 or rock, which, if carefully removed, and, before they are 

 too dry, spread on white paper, will exhibit a most beauti- 

 ful and pleasing variety without the trouble of drawing. 

 I am, sir, your most humble servant, 



James Graham. 



Berwicloup on-Tee d, , -~ 



Feb 1, 1809. 



XXXIV. A Letter on the Alterations that have taken place 

 in the Structure of Rocks, on the Surface of the basaltic 

 Country in the Counties of Deny and Antrim. Addressed 

 to Humphry Davy, Esq., See. R. S. By William 

 Richardson, D. D. 



[Concluded from p. 116.] 



Inquiry into the Formation of our perpendicular Facades. 



At is natural that the first great operation we proceed to in- 

 vestigate, should be the formation of our magnificent fa- 

 cades, one of which is the principal subject of this memoir. 



The line of coast that bounds our basaltic area on its north 

 side, extends about twenty-five Irish miles, in which course 

 the precipices are nearly continuous, and more than one half 

 of them absolutely perpendicular for a great part of their 

 stupendous height. The operation by which they were cut 

 off so abruptly, and left with a formidable aspect towering 

 over our coast, is the one we inquire into. 



That these bold precipices once projected further in many 

 places is easily demonstrated ; at Bea/iyn Daana, and at the 

 Chimney, the columnar construction was obviously once 

 carried much further out. 



At the Milestone, Portcooan, and Portnalau. the fragment? 

 of dykes extend far beyond the face of the precipice. 



These same facts, together with the projecting base, show 

 tfrat these sudden abruptions were not formed by the sub- 

 siding. 



