described, and evidently in a higher situation: it is a calcareous sandstone, and bears a precise resemblance to that which constitutes the whole of the eastern side of Strathaird. Now as no sandstone of this description is found among the lower beds, and as we have clearly traced the order of those from the mica slate to this point, I think that we need not hesitate in placing the sandstone of Strathaird in the situation which I claim for it, the last in the series of the secondary strata. However that shall be determined, I must proceed to describe it. It is to be seen reaching from the termination of the trap on the western side of the promontory, round the point of Aird to nearly die upper end of Loch Slapin, preserving a great evenness of direction and consistency of character throughout this space. I have called it in general a sandstone, although it will be seen that it also contains beds of limestone, but in small number and quantity. The position of the leading line of these beds is so generally horizontal that it is never found to vary five degrees, and that variation is so gradual that it will often pass without notice: but it is attended with a disposition so remarkable, that I think it necessary to point it out, and as it is difficult to render it intelligible in words, I have added a diagram[1] for illustration.
Each bed seems compounded of two parts, the one a single horizontal
lamina, and the other a series of inclined ones, or, there is a regular
alternation of a set of inclined laminæ with one horizontal
one. These are perfectly defined, since the intervals are deeply
channelled by the weather, the whole having the aspect of some
of the carved ornaments of Saxon architecture. This appearance
gives on a first view the impression as of a regular series of beds,
alternating with each other, of which the one is horizontal, and
- ↑ Pl. 4. fig. 1.
