[Frost and fire : natural engines, tool-marks and chips : with sketches taken at home and abroad by a traveller] . falls, is acoarse sandstone or conglomerate. The upper valley is aroimded hollow, at the bottom of which the river has dug ashallow trench. The upper hollow ends in a steep slope ; andthe lower valley, like the upper, is a rounded curved rock-groove, through which the river meanders ; but the bottom ofthe gioove is covered with beds of gravel. Both theseglens, the slope, and the surrounding hOls, bear marks ofice; so the river did not hew out the glens; but it has duga narrow tren
[Frost and fire : natural engines, tool-marks and chips : with sketches taken at home and abroad by a traveller] . falls, is acoarse sandstone or conglomerate. The upper valley is aroimded hollow, at the bottom of which the river has dug ashallow trench. The upper hollow ends in a steep slope ; andthe lower valley, like the upper, is a rounded curved rock-groove, through which the river meanders ; but the bottom ofthe gioove is covered with beds of gravel. Both theseglens, the slope, and the surrounding hOls, bear marks ofice; so the river did not hew out the glens; but it has duga narrow trench m the slope, and it is sorting the debris in thelower glen. The notch in the slope is 700 feet deep ; androunded water-marks are clearly seen on the steep walls ofthe gorge, from top to bottom. The fall is working rapidlyup stream ; digging at the bottom of the pool, at the foot ofthe rock ; undermining, sawing, and working back into theslope. It leaps out of the pool with a wild roar ; the bedof the stream is cumbered with enormous stones. Whereundermined cliffs have fallen, long banks of talus slope down. RIVERS. 9^ to the waters edge, ready to be swept away, and sorted lowerdown. The tool, the mark, and the chips, are together ; andthe power of the engine is displayed in the work. On one point it is possible to lie on a long flat stone, lookover, and drop pebbles from the outspread hands, 700 feetdown into the gorge. If a fall of undermined rock chokes the stream in this bigditch, there will be a deep lake in the slope between the water will fall harmlessly into it, and the rate of wearingand scene of action will change. The water will work mostbelow the dam, till it is removed, and then the lake will dis-appear, and the river will begin at the bottom of the old fallagain. But the sides of the trench will be angular wherefractured, or smoothed where water-worn ; the torrent-markwill continue like the letter (J ploughed out of the bottom of the curved glen s •.
Size: 1326px × 1885px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookpublisheredinburghsn, booksubjectgeo, booksubjectmeteorology
