THE LUMBER TRADE. 
273 
While, then, without much injury to the younger growths, the 
native forest will bear several u cuttings over ” in a generation 
—for the increasing value of lumber brings into use, every 
four or five years, a quality of timber which had been before 
rejected as unmarketable—a fire may render the declivity of a 
mountain unproductive for a century.* 
Different woods vary greatly in combustibility, and even when their bark 
is scarcely scorched, they are, partly in consequence of physiological char¬ 
acter, and partly from the greater or less depth at which their roots habit¬ 
ually lie below the surface, very differently affected by running fires. The 
white pine, Pinus strobus , as it is the most valuable, is also perhaps the 
most delicate tree of the American forest, while its congener, the Northern 
pitch pine, Pinus rigida , is less injured by fire than any other tree of that 
country. I have heard experienced lumbermen maintain that the growth 
of this pine was even accelerated by a fire brisk enough to destroy all 
other trees, and I have myself seen it still flourishing after a conflagration 
which had left not a green leaf but its own in the wood, and actually 
throwing out fresh foliage, when the old had been quite burnt off and the 
bark almost converted into charcoal. The wood of the pitch pine is of 
comparatively little value for the joiner, but it is useful for very many pur¬ 
poses. Its rapidity of growth in even poor soils, its hardihood, and its 
abundant yield of resinous products, entitle it to much more consideration, 
as a plantation tree, than it has hitherto received in Europe or America. 
* Between fifty and sixty years ago, a steep mountain with which I am 
very familiar, composed of metamorphic rock, and at that time covered 
with a thick coating of soil and a dense primeval forest, was accidentally 
burnt over. The fire took place in a very dry season, the slope of the 
mountain was too rapid to retain much water, and the conflagration was 
of an extraordinarily fierce character, consuming the wood almost entirely, 
burning the leaves and combustible portion of the mould, and in many 
places cracking and disintegrating the rock beneath. The rains of the fol¬ 
lowing autumn carried off much of the remaining soil, and the mountain 
side was nearly bare of wood for two or three years afterward. At 
length, a new crop of trees sprang up and grew vigorously, and the moun¬ 
tain is now thickly covered again. But the depth of mould and earth is 
too small to allow the trees to reach maturity. When they attain to the 
diameter of about six inches, they uniformly die, and this they will no 
doubt continue to do until the decay of leaves and wood on the surface, 
and the decomposition of the subjacent rock, shall have formed, perhaps 
hundreds of years hence, a stratum of soil thick enough to support a full- 
grown forest. 
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