On each side of a long, hollow, deep valley, bounded by dark and lofty mountains, at elevations respectively of 1266, 1188, and 980 feet, three strong lines are traced on the mountain-sides, parallel to each other and to the horizon, and at levels exactly corresponding on the opposite slopes,—so extraordinary in their appearance as to impress the most unphilosophical and incurious spectator.

These singular and solitary phenomena, although long known and celebrated by the Highlanders of that wild region as the traditional opposite slopes,—so extraordinary in their appearance as to impress the most unphilosophical and incurious spectator.

These singular and solitary phenomena, although long known and celebrated by the Highlanders of that wild region as the traditional works of their great ancestors, remained unnoticed by science and the world at large, until that indefatigable disturber of hidden mysteries, animals, and antiquities, the tourist Pennant, published in 1769 a short account of Glen Roy, in his ‘Tour through England, Wales, and Scotland.’

A second description appeared in the ‘Statistical Survey of Scotland,’ in 1793.

The subject was next taken up by Macculloch, who published an admirable paper, illustrated with views, maps, and sections, in the Transactions of the Geological Society for 1817. “So rarely,” he remarks, “does nature present us in her larger features with artificial forms or with the semblance of mathematical exactness, that no conviction of the contrary can divest the spectator of the feeling that he is contemplating a work of art,—a work, of which the gigantic dimensions and bold features appear to surpass the efforts of mortal powers.