APPENDIX. 33 



The Scotch fir, a, is only reprefented as having the 

 whole tier of branches, which, in the execution, is the 

 cafe throughout. The dotted lines, b, fhew the part 

 of the fir under the furface, where part of the lower 

 tier is reprefented alfo below the furface, to keep it 

 firm, as has been already obferved. In fome cafes the 

 whole of the lower tier is below the furface, and when 

 that takes place, the fir is let down to the fecond tier ; 

 this is necefTary in boggy or fandy foils, which may be 

 difficult to comprefs. 



In forming this kind of fence, the laft two years 

 growth is cut away, being confidered too weak. la 

 general, two years growth is below the furface, and 

 the growth of four or five years appears above it, after 

 cutting off the weak growth. 



It is fcarcely neceflary to remark, that the more luxu- 

 riant the trees are, the greater the diflance they may 

 be placed afunder, and vice verfa. 



In dry fituations, permanent fences of thorn, beech, 

 &c., of a fmall fize, are generally placed behind this 

 cbcvaux-dt-frife work, which, in the courfe of four or 

 five years, becomes fubflantial enough to guard againft 

 cattle, this being about the period the temporary fence 

 will laft. In moift fituations, alder and mountain-afh 

 are introduced, and, after being two feafons planted, 

 are formed into a kind of hoop, four feet above the 

 furface, which is found to mike a complete fence 

 againft cattle, when the other has gone to decay. In 



R 2 many 



