BOTANY IN RELATION TO STUDY OF TIMBER. 47
spp.). It is an excellent wood for carving, and is also used
by curriers for cutting-boards because the knife moves across
it in any direction with equal ease. The wood of the British
trees is not much used, but that of the American Basswood (Tilia
americana) is extensively used for cheap furniture, turnery, etc.
Another use is for the manufacture of wood wool, its value in
this direction tying in the fact that its shavings do not impart
a taste to foods packed therein. Three other soft even-textured
timbers are Willow (Salix spp.), Poplar (Populus spp.) and
Horse Chestnut (Aesculus Hippocastanum). These three woods
are very similar in structure, and are only to be distinguished
with certainty on microscopic examination. Horse Chestnut
wood is of little value, and is used for the backs of cheap brushes,
especially scrubbing brushes, because of its clean white appear-
ance. It is also used to some extent for toys. Both Willow and
Poplar are fire resistant, and for this reason Poplar flooring
is sometimes used in factories. A floor made of this wood has
an additional advantage in factories where heavy castings have
to be shifted, in that the wood is soft and gives under a weight,
so that there is little danger of damage to the castings if they are
bumped on the floor. Willow is a useful wood for lining brake-
blocks : apart from its fire resisting properties it never wears
to a very smooth surface, and in consequence grips the wheel
well. Owing to its resilience the wood is favoured by the
maker of artificial limbs, while for the same reason it is used
for making cricket bats. Only the wood of Salix caerulea is used
for the best bats, and it would be of great interest to discover
why other Willows, or even Poplars, are not as suitable for the
purpose, when they are almost identical in structure. This is
one of the many points which serves to show that the study of
timbers with a view to their utilisation is one that must be
approached from more angles than that of plant anatomy alone.
BIBLIOGRAPHY.
The literature dealing with wood is large. The books in the
following list are either of a general nature, or deal more par-
ticularly with British timbers ; some contain extensive biblio-
graphies.
—————Official Guide to the Museums of Economic Botany : No. 3.
Timbers and Gymnosperms Kew, 1927.