Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/44

34 latter having Snei-feldt almost in the centre, comprehends the highest ground and the mountains of North Bor-roilva, Gob-y-Scioot, little and big Snei-feldt, Bein-y-phot, Kanaghyn and North-Greebah.

A boggy and elevated table-land lies on both sides of the central line of mountains, separating it from the two exterior ones. The summits of the extensive mountains do not all of them greatly surpass the elevation of the intervening table-land itself.

In the southern district of the group, the two exterior and skirting lines of mountains do not exist, but the eastern side of the mountains is rather scooped out and smoothed into a gentle and gradual declivity; whereas the western side constitutes a range of cliffs abrupt in most of its extent.

The steepness of the exterior mountains is nearly the same on each side. The northern boundary of the group terminates almost abruptly, and beyond the Curragh, lie the Balla-chyrrim hills, a low range formed of loose sand and gravel, facing the northern escarpment of the group, and then passing southwards in a parallel direction between the coast and the western exterior line of mountains.

A little to the north of the Balla-chyrrim hills, is a shingly beach, insensibly declining towards the sea, and formed of water-worn pebbles and sea-sand. The latter is hardened and binds the pebbles strongly together. It is the opinion of several persons in the isle, that the land in this quarter is gaining sensibly upon the sea. Some go so far as to say that the increase is not less than two yards in a year.

There are but few water-courses of any magnitude and extent in the Isle of Man. Sulby River the largest of all, irrigates the Curragh, and from the village of Sulby to Ramsey where it