37a PLEASANT WA YS IN SCIENCE. 



which would be cut off by two lines drawn from the head of 

 Loch Rannoch, one towards Inverness and the other to 

 Stonehaven." The total length of various rivers in this 

 region which were flooded amounted to between 500 and 600 

 miles. Their courses were marked everywhere by destroyed 

 bridges, roads, buildings, and crops. Sir T. D. Lauder 

 records " the destruction of thirty-eight bridges, and the 

 entire obliteration of a great number of farms and hamlets. 

 On the Nairn, a fragment of sandstone fourteen feet long 

 by three feet wide and one foot thick, was carried about 200 

 yards down the river. Some new ravines were formed on 

 the sides of mountains where no streams had previously 

 flowed, and ancient river channels, which had never been 

 filled from time immemorial, gave passage to a copious 

 flood." But perhaps the most remarkable effect of these 

 inundations was the entire destruction of the bridge over the 

 Dee at Ballater. It consisted of five arches, spanning a 

 waterway of 260 feet The bridge was built of granite, 

 the pier, resting on rolled pieces of granite and gneiss. 

 We read that the different parts of this bridge were 

 swept away in succession by the flood, the whole mass of 

 masonry disappearing in the bed of the river. Mr. Farqu- 

 harson states that on his own premises the river Don forced 

 a mass of 400 or 500 tons of stones, many of them of 200 or 

 300 pounds' weight, up an inclined plane, rising six feet in 

 eight or ten yards, and left them in a rectangular heap about 

 three feet deep on a flat ground, the heap ending abruptly at 

 its lower extremity." At first sight this looks like an action 

 the reverse of that levelling action which we have here 

 attributed to water. But in reality it indicates the intense 

 energy of this action ; which drawing heavy masses down 

 along with swiftly flowing water, communicates to them so 

 great a momentum, that on encountering in their course a 

 rising slope, they are carried up its face and there left by the 

 retreating flood. The rising of these masses no more 

 indicates an inherent uplifting power in running water, than 

 the ascent of a gently rising slope by a mass which has relied 



