AMEEICAIT FOEEST-TREES. 321 



In Georgia and in Alabama, Lyell saw " tlie beginning of tbe 

 formation of hundreds of valleys in places where the primitive 

 forest had been recently cut down." One of these, in Georgia, 

 in a soil composed of clay and sand produced by the decompo- 

 sition in situ of hornblendic gneiss with layers and veins of 

 quartz, " and which did not exist before the felling of the for- 

 est twenty years previous," he describes as more than 55 feet 

 in depth, 300 yards in length, and from 20 to 180 feet in 

 breadth. Our author refers to other cases in the same States, 

 " where the cutting down of the trees, which had prevented the 

 rain from collecting into torrents and running off in sudden land- 

 floods, has given rise to ravines from TO to 80 feet deep." * 



Similar results often follow in the Northeastern States from 

 cutting the timber on the " pine plains," where the soil is usually 

 of a sandy composition and loose texture. 



American Forest-Trees. 



The remaining forests of the Northern States and of Canada 

 no longer boast the mighty pines which almost rivalled the 

 gigantic sequoia and redwood of California ; and the growth of 

 the larger forest-trees is so slow, after they have attained to a 

 certain size, that if every pine and oak were spared for two cen- 

 turies, the largest now standing would not reach the stature of 

 hundreds recorded to have been cut within two or three genera- 

 tions.f Dr. Williams, who wrote about sixty years ago, states 



* Lyell, Principles of Oeology, 10th ed., vol. i., pp. 345-6. 



f The growth of the white pine, on a good soil and in open ground, is 

 rather rapid until it reaches the diameter of a couple of feet, after which it is 

 much slower. The favorite habitat of this tree is light, sandy earth. On this 

 soil, and in a dense wood, it requires a centuiy to attain the diameter of a 

 yard. Emerson {Trees of Massachusetts, p. 65) says that a pine of this species, 

 near Paris, " thirty years planted, is eighty feet high, with a diameter of three 

 feet." He also states that ten white pines planted at Cambridge, Massachu- 

 setts, in 1809 or 1810, exhibited, in the winter of 1841 and 1842, an average 

 of twenty inches diameter at the ground, the two largest measuring, at the 

 height of three feet, four feet eight inches in circumference ; and he mentions 

 another pine growing in a rocky swamp, which, at the age of thirty-two years, 

 " gave seven feet in circumference at the butt, with a height of sixty-two feet 

 six inches." This latter I suppose to be a seedling, the others transplanted 

 trees, which might have been some years old when placed where they finally 

 grew. 



The following case came under my own observation : In 1824 a white-pine 

 14* 



