12 
THE GE01;0GIST. 
first, as tlie result of vertical pressuro applied to the columns after 
their perfect formation, and before the mass had quite lost its 
plasticity from heat ; secondly, the effect of a re-hoating and 
compression on the columns by an incandescent mass of trap being 
poured out on them, thus rendering them plastic to a certain depth 
only, an idea not improbable when it is recollected that basalt fuses 
at a loss heat than that required to melt pig-iron. Near Portrush, on 
the Coleraine road, an excavation into a low Icnoll of amorphous trap, 
the base of which is formed of a thick bed of columnar basalt, affords 
a striking example of perfectly formed vertical columns being bent 
over at the top to the depth of a few feet, most likely the re- 
sult of their having been re-heated and compressed by the super- 
imposed amorphous trap. The foregoing remarks have of course no 
reference to columnar masses which exhibit a radiating structure, as 
tliis may be merely a rude zeoHtic form of colnmnar arrangement, or 
crystallization in the basalt. 
Leaving the Causeway, and proceeding along the base of the cliffs 
south west towards the headland called " Weirs snoot," (two hundred 
and eighty-five feet in elevation), we soon pass off the Causeway-bed, 
as it rises to that direction," or, in other words, slopes to the east- 
ward ; and, as we get near the Hotel, the pathway imder the cliffs ex- 
poses the lost ochre bed of the Chimney-headland ; it is here, 
however, very thin, and is overlaid by the western extension of the 
amorphous trap which was described as resting on the '• Organ"-bed, 
or that which forms the Giant's Causeway. The base of this amoi-- 
plious trap is rudely columnar to the height of from eight to ten feet 
from the ochre-bcd, the sides of the imperfectly formed pillars being 
deeply waved or curved, giving them a pinched look. Many of these 
columns if detached would resemble a long irregularly shaped wedge 
or pyramid, the base or apex being up or down as chance would 
have it. 
The exceedingly close resemblance of this rudely columnar mass 
to that of the Rowley Hill, near Dudley, in Staffordshire, is very 
striking, though they are of different geological age. 
The rugged headland to the north of the Causeway Hotel, called 
" the Great Stcucan," and the chff called " Weirs snoot," are formed 
of the amoii^hous basalts which underlie the ochre-bed, and con- 
