EPl'ECTS O^ SHADES ON VEGETATION. 231 



ry Valuable for many mechanical purposes, which require so- 

 lidity and durability. It will propogate itself, too, in the most 

 barren places, where the soil is even so light as to be blown a- 

 way by the winds. By sheltering such places, and dropping 

 its leaves on thera, it causes a sward to grow over them, and 

 grass to grow upon them. It is, however, objected by some, 

 that it is not advisable to plant the locust on the borders of 

 fields, on account of their spreading too much, by scattering 

 their leaves, unless on those which are most barren. This ob- 

 jection, however, it would seem, might be obviated, when the 

 field to be enclosed by the locust was often to be appropriated 

 to the purposes of tillage, especially to the culture of the hoe, 

 by which every superfluous plant may be suppressed. 



It is of importance to the ^rmer, when' making a new settle- 

 ment, to ascertain, by observation, the effects of the various 

 forest trees, on vegetation, that he may be able to decide cor- 

 rectly respecting what ones are most proper to be left stand- 

 ing on the borders of his fields. 



In some of the best cultivated parts of Europe, as well as A- 

 merica, the border of the field adjoining the highway, is often 

 found ornamented with either a natural or artificial row of 

 trees, such as are found least injurious to vegetation ; and 

 w-hich are often, too, appropriated as important constituents of 

 the fence. 



It is believed that the shades of many other trees, that have' 

 not been mentioned in this essay, will be found to be but little 

 injurious to many of our valuable plants.- 



So far as this inconvenience can be avoided, it is h(i)ped the 

 disposition for the destruction of our trees generally, will be 

 less prevalent. Monsieur Mihaux, in his work on the forest 

 trees of North America, in stating the causes which induced so 

 general a destruction of them in this country, observes : "The 

 cost and expense of clearing our lands, compared with their 

 value after they were cleared, and the difficulty of eradicating 

 completely the after growth,, were so great, and the forests 



