56 Soil- Binders 



without breaking. The roots of the Lucerne clover 

 are said to be often as strong as those of an ash-tree, 

 though, of course, very much finer, and looking much 

 Weaker; and they have at times given unmistakable 

 proof of their strength, not merely by resisting the 

 advance of the ploughshare, but by actually break- 

 ing it. 



It is this wonderful tenacity which makes roots so 

 useful in binding the soil together, and in keeping the 

 banks of streams and rivers, as well as sea-dikes, from 

 being seriously undermined. 



On mountain slopes, too, the roots of trees and 

 brushwood serve to keep in its place the soil which 

 must else slip down by its own weight, even if there 

 were no rain to wash or wind to blow it. And where 

 people have been so short-sighted as to cut down 

 mountain forests, there they have had to lament 

 not merely the ruin, but the actual loss, of the fields 

 in their vicinity, which have been carried bodily 

 away. 



In some parts of the French Alps half the cultivated 

 ground has been washed away, owing to the reckless 

 destruction of the pines ; and this is not all, for when 

 the forests are gone, not only does the soil follow, but 

 so do the avalanches ; or rather they come ! plunging 

 down from the heights above and overwhelming every- 

 thing in their way. The trees, and the trees only, 

 were strong enough to resist them. 



It is remarkable what a very slight obstacle is often 

 enough to stop the onward motion of a sand-drift, a 

 few oleanders, by no means very sturdy shrubs, being 

 often found sufficient for the purpose in the Bermudas. 

 A sand-drift cannot, of course, compare with an 



