Modern Painters

This is an OCR edition with typos. Excerpt from book: CHAPTER III. OF THE INFERIOR MOUNTAINS. We have next to investigate the character of those inter- % 1. The inferior mediate masses which constitute the greater uMed "f£m part of all hill scenery, forming the outworks to! "iMdedtato of the high ranges, and being almost the sole hed". constituents of such lower groups as those of Cumberland, Scotland, or South Italy. All mountains whatever, not composed of the granite or gneiss rocks described in the preceding chapter, nor volcanic, (these latter being comparatively rare,) are composed of beds, not of homogeneous, heaped materials, but of accumulated layers, whether of rock or soil. It may be slate, sandstone, limestone, gravel, or clay ; but whatever the substance, it is laid in layers, 7iot in a mass. These layers are scarcely ever horizontal, and may slope to any degree, often occurring vertical, the boldness of the hill outline commonly depending in a great degree on their inclination. In consequence of this division into beds, every mountain will have two great sets of lines more or less prevailing in its contours-one indicative of the surfaces of the beds, where they come out from under each other-and the other indicative of the extremities or edges of the beds, where their continuity has been interrupted. And these two great sets of lines will commonly be at right angles with each other, or nearly so. If the surface of the bed approach a horizontal line, its termination will approach the vertical, and this is the most usual and ordinary way in which a precipice is produced. Farther, in almost all rocks there is a third division of sub., c 2 Portlier divl stancei which gives to their beds a tendency ion of these hcd to split transversely in some directions rather hy loints. ' ' . than others, giving rise t... --This text refers to the Paperback edition.