nual increment of 3 cords of wood per
acre. On the same area a forest of Scotch Pine increases every year by
2.4 cords on the best soil, 2 cords on medium soil, and 1.5 cords on
poor soil.

But notwithstanding the splendid qualities which distinguish the White
Pine as a forest tree its wood has never been looked upon with favor
in Europe. Many of those who are cultivating the White Pine for
business seem to expect that they will raise a heavy and durable wood.
These are the qualities prized in their own timber trees, and they
seem to think that the White Pine must be so highly prized at home for
the same qualities, when in fact it is the lightness and softness of
the wood which are considered in America. It would seem also that some
European planters believe that a Pine tree exists which will yield
more and at the same time heavier wood than any other tree on the same
area. It is a general rule that the amount of woody substance annually
formed on the same soil does not vary in any great degree with the
different kinds of trees. For instance, if we have good soil we may
raise 2,200 lbs. per acre of woody substance every year, from almost
any kind of timber tree. If we plant a tree forming a wood of low
specific gravity, we get a large volume of wood, and this is the case
with the White Pine. If we plant on the same ground an Oak tree, we
will get small volume of wood, but the weight of the woody substance
will be the same, that is, 2,200 pounds of absolutely dried wood per
acre.

It is remarkable that there is hardly any difference in the specific
gravity of the wood of the White Pine grown in Europe and in its
native country. I collected in Central Wisconsin wood-sections of
a tall tree and compared the specific gravity with the wood of a
full-grown tree of White Pine from a Bavarian forest. The average
specific gravity of the Bavarian tree was 38.3. The average specific
gravity of the American tree was 38.9. In both trees the specific
gravity slightly increased from the base to the top. Professor Sargent
gives 38 as the result of his numerous and careful investigations.

I was much surprised that the thickness of the sap-wood varied much in
favor of the Bavarian tree.

The sap-wood measured in thickness:

Of the Bavarian tree. Of the American tree.
At the base 2.7 centimeters 9 centimeters.
In the middle .4 " 6 "
Within the crown .3 "