Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/173

 offered only conjectures on the similarity of the series, I do not find those conjectures verified; the position of the beds becoming first vertical and then reversed and irregular; ultimately settling in a dip towards the east, the reverse of that which predominates on the western or upper side of the series. But whatever irregularities are found in the dip, there are none in the direction, which with a slight local disturbance near Ord is invariably rectilinear, and on the north-east line or nearly so.

On the north-eastern end of this series, where it forms the mountains of the Kyle, the rocks can be traced perfectly from the gneiss at Isle Oransa to the commencement of the limestone near Broadford, this space comprising the collective thickness of the strata; but through this tract the quartz rock or indurated sandstone is predominant. If these strata are prolonged toward the south-west their characters change, or they are discontinuous in composition according to the line of their direction, since the schist and quartz rock are most abundant toward the north-eastern end, while red sandstone prevails at the opposite one.

The space which they have been represented to occupy on the original map must also be extended, and to a certain degree this may be done by prolonging the line of direction from that point near Isle Oransa where the junction of the gneiss is found.

I have already related the error committed by allowing too much space to the micaceous schist, which occurs only as one of the members of a series principally formed of gneiss and chlorite schist. Another of the sources of that error will now appear when I describe the last enumerated member of the red sandstone series; and it will no less excite surprise than operate as a caution in the present state of geological science, against judging of rocks by analogies, or by any other evidence than that of actual and careful examination.