180 
THE GEOLOQiST. 
years will witness its complete destruction. Some very interesting 
historical associations are connected with this spot, and the readers 
of Scott will regard it with increased interest when they remember 
that AVilliam Christian, of Ronaldsmay, was shot here in 1662, for 
surrendering the island to Cromwell's army. 
To this period also belong the numerous natural arches and caves 
found along the coast ; probably, however, most of them belong 
mainly to the later portion of the Pleistocene age. They are found 
on all parts of the island, wherever the nature of the coast-line was 
favourable to their formation. Many of them run considerable dis- 
tances into the cliffs, frequently winding tortuously ; in other in- 
stances they are merely deep straight chambers in the rocks. They 
are usually but little elevated above the existing high-water mark, 
and appear to contain only the ordinary shingle and sand of the 
neighbouring shore. The most remarkable of these arches and caves 
are those on the M'estern side of Langness. The rocks there are 
greatly dislocated by the intrusion of several greenstone dykes, two 
of which intersect at this spot, and the strata thus weakened have 
yielded to the action of the waves, an extensive series of arches and 
caves having been the result. One of the most remarkable of these 
is an arch about twenty-six feet wide, fifteen feet high, and eighteen 
feet deep. The floor and walls are composed of slaty schists, here of 
a deep claret-colour, thrown up at a high angle, and much contorted 
by the neighbouring greenstone ; the roof is formed of the Old Eed 
conglomerate, which is of the characteristic deep red colour, and rests 
almost horizontally upon the edges of the upturned schists. This 
arch stands a few feet above high-water mark, but it is evidently only 
the relics of what was once a vast cavern, extending far below the 
level of the sea. Its sides (the lower portion consisting of the con- 
torted schists, and the upper of the coarse conglomerate) extend 
seaward from thirty to forty yards beyond the arch itself, a great part 
of this being below high-water, and the partially enclosed space much 
encumbered with huge masses of fallen conglomerate, evidently the 
debris of the broken roof. Several others of the series equal, if they 
do not even exceed, this one in magnitude. One in particular, 
roughly measured by pacing, in its entire state would have been a 
cave fully sixty yards deep, — twenty yards of its depth being below 
high-water, — ten yards wide, and, at its upper end, eight yards high. 
At its upper extremity it is still covered with a roof for about twenty- 
five feet, and its walls are there nearly thirty feet high, sloping thence 
down to the water. These caves and arches present many features 
of great interest, and are deserving of a fuller investigation. The 
occurrence also in this locality of the Cambrian schists, the Devonian 
conglomerate, and the Carboniferous limestone, in their characteristic 
positions, together with the numerous greenstone dykes, make Lang- 
ness, to the geologist, one of the most interesting spots to be found 
in the whole island ; while the wild and rocky nature of its coast, 
and the many picturesque views to be obtained from it of the beau- 
tiful bay and neighbourhood of Castletown, cause it to be a favourite 
place of resort for both natives and visitors. 
