ON HARVESTING BARK. 133 
being laid in heaps as we have described, for twenty shillings 
aton. The value of oak bark, as of other kinds, is exceedingly 
various; we have known it from £4 or £5 up to £8 per ton. 
Birch bark is commonly about the same, but larch bark does not 
exceed one half that price. The sap circulates earliest in the 
larch, and its bark is speedily removed, but it is very light, 
and ill adapted for distant carriage, on account of its bulk, 
which is twice that of the oak bark, and it of late years has 
seldom been manufactured profitably. 
