INTERIOR LAND CHANGES. 



419 



flood of 1829 came down, when the mantle of alluvium was torn off, the corn land and the 

 grove were swept away, and the memorials of manufacturing industry were again exposed 

 to the light. 



The excavating power of water when confined to a channel too narrow for it, and where 



interesting and striking than this event, 



White Mountain in the Alleglianies. 



its bed has a considerable inclination, was 

 strikingly exemplified by an expedient 

 resorted to by Mr. Gumming Bruce, to 

 preserve Thomas Rhymer's Hill upon his 

 estate. The Dornack swept nearly round 

 this conical-shaped hill, which formed the 

 extremity of a long and narrow peninsula, 

 and was rapidly wearing away by the ac- 

 tion of the stream in its floods. The 

 level of the water on one side of the pe- 

 ninsula was about twenty-two feet higher 

 than on the other, and consequently, by 

 cutting a trench through the neck, the 

 stream would be diverted from its old cir- 

 cuitous channel round the hill, and pass 

 directly through the peninsula to that part 

 of its bed in a line with the opening. Ac- 

 cordingly a cut was made, with a fall of 

 about four feet from one end to the other, 

 at a time when the river was of its average 

 size. When the last dam of earth which 

 prevented the egress of the water into the 

 trench was struck away, " nothing," says 

 Sir Thomas Dick Lander, " could be more 

 where the effect of a single blow was, in 



