the objects to which he alludes as the works of art?--most certainly none, they are unquestionably the results of the operation of time and the elements, and have never been formed by any agents except those which Nature employs in the decomposition of granitic masses; but the age of Antiquarian illusion is past; the light of geological science dispels the phantoms which the wizard fancy had created, just as the rising sun dissolves the mystic forms which the most common object assumes in twilight, when viewed through the medium of credulity and superstition. The _rock basins_ of Antiquaries are rounded cavities on the surface of rocks, and are occasionally as spheroidal, internally, as if they had been actually shaped by a turning lathe; it was this artificial appearance which first suggested the hypothesis concerning their origin, and induced the Antiquary to regard them as pools of lustration. Dr. Mac Culloch,[120] however, very justly observes, that their true nature is very easily traced by inspecting the rocks themselves; on examining the excavations they will be always found to contain distinct grains of _Quartz_, and fragments of the other constituent parts of the granite; a small force is sufficient to detach from the sides of these cavities additional fragments, shewing beyond doubt, that a process of decomposition is still going on under favourable circumstances; these circumstances are the presence of water, or rather the alternate action of air and moisture; if a drop of water can only make an effectual lodgement on a surface of this granite a small cavity must be sooner or later produced, this insensibly enlarges as it becomes capable of holding more water, and the sides as they continue to waste necessarily retain an even and rounded cavity, on account of the uniform texture of the granite. This explanation is sufficiently satisfactory; in addition to which it may be further stated, that these very _basins_ not unfrequently occur on the perpendicular sides of rocks,[121] which at once excludes the idea of their artificial origin. The other grotesque and whimsical appearances of rocky masses, such as "_rock idols_, _logan stones_," &c. are to be explained upon the tendency which granite possesses of wearing more rapidly on the parts which are most exposed to the action of the weather, as already explained at page 104. There occurs upon the western part of the ridge of _Carn-breh_ an equipoised stone, about 20 feet in diameter, affording a very singular illustration of these views, and of which we shall here present a sketch to our readers. [Illustration] Thus upon simple and philosophical principles are such appearances to be easily explained, and this _Phantasmagoria_ of the learned antiquary vanishes.