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BETULA VERRUCOSA
Distribution
Northern Europe, including the British Isles, Sweden, Finland and Scandinavia.
The tree
It is a relatively small tree, rarely exceeding 18m in height. In Britain,
where birch is not often encouraged by foresters, the trees are typically
of poor form and the stem is apt to be fluted, but in Scandinavia, where
it is regarded as an important timber tree, the bole is more cylindrical.
The timber
Birch is normally a fairly straight-grained, fine-textured wood of plain
appearance. Occasional trees have irregular grain, giving rise to a highly
decorative figure. It has been found that logs with thin, smooth bark
generally have straight-grained wood while in trees with rough bark the
grain tends to be irregular. The colour is normally white to light-brown
throughout, with no distinct heartwood. The average density is about 0,66,
seasoned.
Technical properties
Birch seasons fairly quickly, with some tendency to warp. When straight
grained it is a good bending wood and is stronger than oak. It is not
durable but is amendable to preservative treatment. It works fairly easily
in most operations and takes a good finish if the grain is reasonably
straight. The timber is excellent for turning, and gives good results
with stain, polish and glue.
Uses
Ordinary straight-grained birch is useful as an inexpensive general utility
wood having a plain appearance, high strength and good working and finishing
properties. Being available in relatively small sizes, it is largely used
for turnery and in the furniture industry for chair parts and upholstery
frames. Most of the birch used for these purposed in Britain is imported,
Sweden and Finland being major sources of supply. In Scandinavia highly
figured wood is used in the form of veneer for decorative work, and in
the solid for fancy boxes, cigarette cased and the like, and there is
no reason why selected English material should not be utilized in the
same way.
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