34 REPORT ON FOREST TREES. 



marks, it is like suddenly removing the plantation a fcAv degrees 

 farther north or south. So it is equally injudicious to allow the 

 plants to become crowded and interlaced, as thereby they exclude 

 too much the light and air and serve to weaken each other. In rear- 

 ing a plantation for timber, the approved rule for hard wood trees is, 

 to have a space between each tree equal to half its height ; and for 

 resinous trees, a space equal to one third the height ; and this should 

 be kept in view from the moment that thinnings commence. The 

 period when these thinnings should begin must depend upon the for- 

 wardness of the trees. If acorns are planted in circles such as we 

 have recommended, they can remain so for two or three years ; the 

 weaker ones can then be carefully drawn out, so as not to disturb 

 those that are to remain, until the plants shall stand three or four 

 feet apart. In the course of seven or eight years, the remaining 

 plants should have attained the height of ten or twelve feet, when 

 the first moderate thinning should take place, and ever after, the 

 rule we have laid down should be carefully followed. 



We have thus, in as brief manner as in our power, presented our 

 views upon the important, though neglected subject of arbori- 

 culture, endeavoring to give them in a practical form, so far as they 

 have gone. "We should like to go farther, and to do all in our pow- 

 er to dispel the common illusion that it takes more than one life-time' 

 to grow a tree. We can, however, do no more than to present the 

 following table of the actual, as well as comparative growth of a 

 variety of trees from the time of planting, until they had made 

 twenty years' growth. The plantation covered six acres in extent, 

 consisting principally of a swampy meadow upon a gravelly soil. 



Lombardy Poplar, 



Abele, 



Plane, 



Acacia, 



Elm, 



Chesnut, 



White Pine, 



Spruce, 



Larch, 



No account is here given of the oak, but Louden and other 



