236 PEUNING. 



run or drip in hot weather. Creosote or " oil of tar " is 

 also an excellent preservative ; while sheet-lead or zinc 

 alone is often most like the lichen upon the bark of 

 old trees, and for any conspicuous or important part, 

 where a large wound has been caused, it may be made, 

 by a few touches of the brush, an excellent imitation of 

 the bark of an old tree. 



7. It frequently happens with trees selected from 

 others closely surrounding them, that at some par- 

 ticular part, or it may be all over the stem, a great 

 quantity of spray is produced ; and in consequence of 

 this, that part of the trunk immediately below becomes 

 disproportionately thick in comparison with the part 

 above. The sap is thus in a great measure obstructed 

 in its ascent to the uppermost branches, and the top 

 of the tree is thereby deprived of its due measure of 

 support and enlargement. In order, therefore, to guide 

 the sap, as it were, in the proper direction up the 

 tree, these branches must be diminished. In doing 

 this, we cut off a few of the small ones close to the 

 main stem, and reduce the others by about one-third 

 their original length, taking care in all cases of short- 

 ening to cut a little above another branch or small 

 twig, in order to preserve the main branch alive, 

 and also to conceal the cut part. In pruning within 

 policy grounds, or in sight of walks or carriage-drives, 

 considerable art is required to conceal from view the 

 wounds inflicted upon the trees. 



8. This is a form of pruning applicable principally 

 to young trees, and the object to be attained is their 

 general proportionate development, as a remedy against 

 undue enlargement of the tree below any great mass 

 of branches, by diminishing which the sap is induced 



