It would be a speculation highly interesting to the geologist, to inquire into the probable early history of the Bell Rock, and the changes produced on it by the wasting effects of the waters of the ocean. When we consider the similarity of the red sandstone of this rock with the Redhead of Forfarshire, and opposite shores of Berwick in the neighbourhood of Dunglass, and take into view that there is a ridge or shallower part of the bottom, which extends a considerable way from the Bell Rock in the direction of these shores, we may infer, that the Rock itself had extended at one time much further. We are also enabled to trace the same formation, penetrating to the northward through Ross-shire, and quite across the kingdom, in a southern direction, to Cumberland. At a period indefinitely remote in the history of the globe, we may therefore imagine that one continuous bed of red sandstone had stretched across the Firth , forming a barrier by which the great collection of waters of the Forth and Tay have been pent up. [Sidenote: Proofs of the Sea having occupied a higher level.] In support of this opinion, we have the most unequivocal proofs of the waters of those friths having formerly occupied a much higher level. Of these we may notice the general appearance of their water-worn shores, and a bed of oyster-shells near Borrowstounness, which has been traced to the extent of three miles in length, and about two fathoms in thickness, lying in their natural state, but now upwards of 35 feet above the present level of the sea. Under these circumstances, and many others which might be adduced, it is not improbable that the Bell Rock has at one time been connected with the opposite coasts; and when we consider the general waste of the land, which is apparent in all directions from the impulse of the sea, it may at least be concluded, that at no very remote period, the Rock has been of much greater superficial extent, and above the level of the highest tides. Nor need we be surprised that such changes upon this remote and insulated spot should have been lost sight of, owing to their gradual and almost imperceptible effects, compared with the short period of the life of man, and in absence of all testimony excepting that which is oral. [Sidenote: Plants.]