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of the Counties of Derry and Antrim. 
The hummock of Dunmull, three miles south-east from 
Portrush, is very beautiful, it stands on the top of a high 
ridge, and is a conspicuous object from all parts of the 
country ; it is exactly circular, its flat surface contains an 
acre, it is completely surrounded by a perpendicular facade 
about twenty-five feet high, and formed by two strata, a 
columnar, and an irregular prismatic, resting upon it. 
From this elevated station, where I had the pleasure of ac- 
companying you, I shewed you at six or seven miles distance 
to the westward, among the Derry mountains, the still loftier 
hummocks of Altabrian and Sconce , hemispherical in form, 
composed of but one stratum each, while their swelling- 
out bases displayed accumulations of many more : and also 
near those the hummock of Fermayle, resembling Dunmull, 
but much larger, and also, surrounded by a fa$ade composed 
of two strata. 
I shewed you also at twenty miles distance to the south-east, 
the gigantic Slemish, one of our basaltic hummocks, magnified 
(as it were) into a lofty and insulated mountain, completely 
stratified from its base to its flat summit. 
I shewed you likewise from the bottom of its ridge, the 
neat but diminutive hummock, called the Rock of Clogher , 
above Bushmills. As our time was precious, you took my word 
for its stratification being precisely similar to that of Dunmull. 
There are many other basaltic hummocks scattered over 
the surface of our area, all of them either stratified or por- 
tions of strata ; two of the most remarkable are the hill of 
Knock Loughran, near Maghera, and a tall hummock (whose 
name I forget) a mile eastward from Lisanoure . 
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