Edinburgh New Philosophical Journal (1839 Edinburgh New Philosophical Journal edinburghnewphil27edin Year: 1839 - 1839 396 The Parallel lioads of Glen Boy. they are entirely obliterated ; for instance, when they crosB bare rock, where loose matter would not rest, and when the surface of the hill is gently inclined, because their slope there coincides with that of the alluyial cover. Very often their appearance is so faint, that a spectator may find himself standing on one without being aware of its existence; but at other parts they swell out into pretty broad terraces; and what seemed obscur
Edinburgh New Philosophical Journal (1839 Edinburgh New Philosophical Journal edinburghnewphil27edin Year: 1839 - 1839 396 The Parallel lioads of Glen Boy. they are entirely obliterated ; for instance, when they crosB bare rock, where loose matter would not rest, and when the surface of the hill is gently inclined, because their slope there coincides with that of the alluyial cover. Very often their appearance is so faint, that a spectator may find himself standing on one without being aware of its existence; but at other parts they swell out into pretty broad terraces; and what seemed obscure to a spectator in juxtaposition with it, becomes more distinct when seen from the opposite side of the valley, where the eye takes in the line for a length of some miles, and the obscure parts and the well marked parts are seen in connexion. Each of these shelves or terraces has been found by levelling to be perfectly horizon- tal, both lengthwise and on the opposite sides of the valley. In the annexed figure, '^let h h represent a portion of the surface of the hill, consisting of rock, with a layer of clay and gravel resting upon it, as indicated by the uneven line. The Parallel Roads consist of thicker portions of this alluvial cover, projecting slightly like a shelf or terrace. The first or lowest terrace a, is 972 feet above the level of the sea. The second, b, is 212 feet higher, or 1184 feet above the sea. The third, c, is 182 feet higher than the second, or 1266 feet above the sea. The shelves slope inward to the centre of the valley, (to the line C, B, A). In the adjoining valley of Glen Gloy, separated by an isthmus of high ground half a mile broad, there is a terrace twelve feet higher than c, or 1278 feet above the sea, but none lower. There is a remnant of a similar terrace at Kil- finnin, fom' miles northward, which is forty feet higher than c, or 1306 feet above the sea. The three terraces of Glen Roy follow the line of the valley down to its junction with Glen
Size: 1006px × 1987px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
