ses underlying the formation of early and late wood. Several
factors may be involved. In conifers, at least, rate of growth
alone does not determine the proportion of the two portions of
the ring, for in some cases the wood of slow growth is very hard
and heavy, while in others the opposite is true. The quality of
the site where the tree grows undoubtedly affects the character
of the wood formed, though it is not possible to formulate a
rule governing it. In general, however, it may be said that
where strength or ease of working is essential, woods of
moderate to slow growth should be chosen. But in choosing a
particular specimen it is not the width of ring, but the
proportion and character of the late wood which should govern.

In the case of the ring-porous hardwoods there seems to exist a
pretty definite relation between the rate of growth of timber
and its properties. This may be briefly summed up in the general
statement that the more rapid the growth or the wider the rings
of growth, the heavier, harder, stronger, and stiffer the wood.
This, it must be remembered, applies only to ring-porous woods
such as oak, ash, hickory, and others of the same group, and is,
of course, subject to some exceptions and limitations.

In ring-porous woods of good growth it is usually the middle
portion of the ring in which the thick-walled, strength-giving
fibres are most abundant. As the breadth of ring diminishes,
this middle portion is reduced so that very slow growth produces
comparatively light, porous wood composed of thin-walled vessels
and wood parenchyma. In good oak these large vessels of the
early wood occupy from 6 to 10 per cent of the volume of the
log, while in inferior material they may make up 25 per cent or
more. The late wood of good oak, except for radial grayish
patches of small pores, is dark colored and firm, and consists
of thick-walled fibres which form one-half or more of the wood.
In inferior oak, such fibre areas are much reduced both in
quantity and quality. Such variation is very largely the result
of rate of growth.

Wide-ringed wood is often called "second-growth," because the
growth of the young timber in open stands after the old trees
have been removed is more rapid than in trees in the forest, and
in the manufacture of articles where strength is an important
consideration such "second-growth" hardwood material is
preferred. This is particularly the case in the choice of
hickory for handles a