Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/69

 stances is often found in the same place, but their order can never be ascertained, for, the cliffs rising to a height of 500 feet or more, they are so far out of reach as to prevent us from forming an accurate judgment respecting the individual parts. It is only by examining the fallen specimens that we can ascertain the number of the varieties in any spot. They seem to me greater from Loch Bracadale to Loch Brittle than elsewhere, but possibly this opinion may only have arisen from the greater facility which I experienced in examining this line of the coast. I have in several places attempted to count the number of strata, and they seem to vary from eight or nine to twelve, fifteen, or even more, but it is not easy to define their boundaries at the distance from which they must be viewed. The way in which the several beds decompose often adds a very remarkable feature to the cliffs: some become scoriform, others moulder into large cavernous shapes, while a third set fall to powder; and these various appearances, combined with the colours of the iron clay, give to the whole that aspect of having undergone the action of fire, which strikes a common observer even more forcibly than a geological one.

I must now proceed to describe the trap which forms the mountains, and which is not entirely limited to the Cuchullin hills, since it is found constituting a great portion of Blaven, as well as parts of the hill of Glamich, and of others whose names cannot be ascertained, but of which the predominant parts are syenite and clinkstone. I have no means of defining their limits with greater accuracy, partly because there is no sufficient map, and partly because the country is nearly impassable in many places, and in others quite inaccessible.

I have attempted to trace at the foot of Garsven, the southernmost of the Cuchullin, the point where the stratified trap ceases and