Jo TIMBER AND TIMBER TREES. [chap. 



to many defects from the want of shelter from cold winds 

 and other exigencies of the environment, including the 

 occasional breakages of the branches from various causes, 

 and the injudicious lopping or pruning which is too often 

 practised. 



Trees grown in a copse might be expected to unite 

 the leading characteristics of the two forms of growth 

 just mentioned, inasmuch as, while the underwood 

 remained, the upward tendency of the stem would be 

 almost as strong as in a forest-grown tree, while each 

 time the copse was cut, the branches would have perfect 

 freedom of growth. It is, however, found that, although 

 forming curved branches and a greater length of stem 

 - than can be met with in isolated trees, instead of the 

 wood being uniformly harder, the changes to which the 

 trees are subjected by the periodical growth and loss of 

 the protecting underwood renders the quality of such 

 timber extremely variable. 



Variety of soil also exercises an influence, both direct 

 and indirect, upon the quality of timber ; trees grown in 

 a dry, rocky soil having generally hard, compact wood ; 

 while the wood of those grown in swampy and moist 

 situations will be found comparatively soft and spongy 

 in texture. Variations of temperature, violent storms, 

 or proximity to the sea or large rivers, and many other 

 circumstances also affect the quality and rate of growth 

 of trees. 



It has long been known that the presence of trees 

 tends directly to keep up and render more constant and 

 uniform the water supply, and that the clearing of large 

 forests results, in time, in the drying up of all the springs 

 and watercourses in the neighbourhood. That such an 

 effect is produced is certain, as attention was lately 

 drawn to it by the condition of large tracts of land in 



