GRINULEY — GEOLOGY Or THE ISLE OE MAN. 
173 
viith a few fishing-boats, or darkened, perhaps, by the smoke of some 
passing steamer. Behind this long line of wild and picturesque 
coast rise the mountains of the great central range, occasional breaks 
in the tall coastline, as at Laxey, permitting us to see at a glance 
their vast proportions from their very bases to their cloud-capped 
summits. Far away in the north we can discern the sharp-peaked 
Barrule, and close to it the rounded head of the giant Snafield, appear- 
ing and disappearing as the wind drives the silvery mist across its 
grassy sides. Nearer still, we may mark the successive peaks of 
Bein-y-Phot, Garrachan, and Greebah. Directly in our front rises 
the pointed head of South Barrule, while in the south the range is 
continued through the sharp outlines of Irey-na-Lhaa, and the long 
swelling ridges of the Mull Hills to the Calf itself. We gaze long 
and earnestly on the glorious combination of the sublime and beauti- 
ful before us ; but we rapidly close in with the shore — the dark clifi:3 
tower higher above our heads, and cast a broader shadow over the 
clear green waves ; and suddenly rounding the southern corner of 
the bay, we fire a gun, which is responded to from the shore, and al- 
most at once we are in the midst of the throng and bustle of a fashion- 
able watering-place. 
The general axis of the island is from N.E. to S.W. : within 
this line rise the highest peaks of the mountain-range, and along its 
sides lie the upturned edges of the Manx rocks. At two points in 
this central axis the granite appears at the surface, probably in con- 
sequence of the overlying rocks having suffered extensive denudation 
— near the head of the Dhoon river, about half-way between Laxey 
and liamsey, and on the eastern side of South Barrule. Between 
the granites of these two localities there is an essential difi^'erence, 
the Dhoon granite being a syenite, and of a much finer and firmer 
texture than that of Barrule. The granite of the latter locality is 
extensively quarried for economical purposes. 
Besting upon the granite is a series of slaty rocks, which, as we 
recede from the central axis, passes regularly through the successive 
stages of mica-schist, clay-slate, and grauwacke-slate. Bespecting 
the exact geological age of these rocks it is extremely difficult to 
speak, tlie few organisms hitherto found in them consisting chiefly of 
some imperfectly-preserved fucoids and corals — very uncertain guides. 
Still, taking into account the character of the lower portion of the 
series, -which is undoubtedly metamorphic, and the regular passage 
into the upper and fossiliferous portion — and, further, from a compa- 
rison of the few fossils which have been found in this upper portion 
with those of other localities — it seems to be now admitted that the 
upper portion of these rocks is to be regarded as Lower Cambrian. 
One of the best-preserved of these organisms, obtained from the 
rocks of Douglas, and now in my own collection, has been lately 
identified by an eminent palaeontologist as generically the same with 
an unnamed fucoid from the Cambrians of North AVales. These 
schists attain an enormous vertical development, probably not less 
than from 7000 to 10,000 feet. Their superficial development is also 
