AGENCY OF RIJJNNJNG WATER. 



137 



exerted by running water in removing weighty 

 masses of rock. In the year 1829, during a flood in 

 the Highlands of Scotland, a fragment of sandstone 

 14 feet long, by three feet wide and one foot thick, 

 was carried* about 200 yards down the river. 



The stone bridge over the Dee, consisting of im- 

 mense blocks of granite, which had stood uninjured 

 for 20 years, was also carried away during the same 

 flood; and Mr. Farquharson states that the water 

 forced a mass of 400 or 500 tons of stones, many of 

 them weighing 300 weight, up an inclined plane, ri- 

 sing six feet in eight or ten yards. Mr. Culley also 

 states, that, during a flood among the Cheviot Hills, 

 several thousand tons' weight of gravel and sand 

 were transported by a small rivulet to a great dis- 

 tance to the plain ; and that a bridge then building 

 was carried away, some of the arch stones of which, 

 weighing three quarters of a ton, were carried two 

 miles down the stream. A rock also, weighing two 

 tons, was transported by the torrent at the same 

 time to the distance of a quarter of a mile. 



The influence of running water in excavating 

 rocks is well known, especially in limestone dis- 

 tricts. At Trenton Falls, in this state (N. Y.), there 

 is some of the most romantic and beautiful scenery, 

 produced by a creek having worn a deep notch 4n 

 secondary limestone to the depth of 100 feet or 

 more, between the perpendicular banks of which it 

 tumbles over several precipices, foaming and roar- 

 ing ; while, over head, the cedars and other ever- 

 greens gracefully bend from either bank, forming a 

 beautiful arch in the centre. In like manner, the 

 Genesee River near Rochester, the Connecticut at 

 Bellows Falls and at Haddam, the Shenandoah at 

 the Blue Ridge, and the St. Lawrence from the 

 fallsf to near Lake Ontario, all have worn deep 



*Lyell. 



f Lake Erie is about 330 feet above Lake Ontario, and the 

 distance between them 32 miles. On flowing out of the upper 



