162 



AKE SOILS EXRICHED, IMPOVERISHED, pt. in. 



of August, 1826, in the White Mountains in New 

 Hampshire, says : ' The natural excavations com- 

 menced generally in a trench a few yards in depth, 

 and a few rods in width, and descended the moun- 

 tains, widening and deepening till they became vast 

 chasms.' This was the effect of one continuous heavy 

 rain. 



And in the present day we may see ravines begun 

 by the accidental results of many operations of man. 

 A hedge or ditch, a pathway, or waggon- way may 

 commence the furrow on the mountain's brow, nay, 

 even on downs wiiich are covered with the closest 

 greensward : and how many of our byeroads and lanes 

 become ravines ! 



Indeed, as the long conduits whose gradients are 

 laid by the wash of rain very generally become the 

 roads or lines of traffic of man, so, vice versa, the 

 roads or lines of traffic of man, on or near declivities, 

 very generally become conduits for the wash of rain. 

 Hence our ' sunk lanes ' and ' sunk roads.' 



In fact, the moment roads or lanes leave the line of 

 the valley, the moment they cross the hills from one 

 valley to another, that m.oment they become more or 

 less sunk roads. And this ' more or less ' depends on 

 the steepness of the hills. That is, the steeper the 

 hill the deeper the sinking of the road. The reason 

 is that roads on declivities are channels for the wash 

 of rain, and they partake of the nature of narrow 

 valleys or ravines. Witliout great care, this sinking 



