552 Thinning of Forest Trees. 



infection, if disease should occur. When kept at regular and 

 sufficient distances, corresponding to their height, by stated 

 thinning, the trees are strengthened by the sun's rays, air, and 

 motion ; and all alpine plants, and such as are exposed to fre- 

 quent agitation from the wind, have a firmer hold of the soil, 

 and live longer, than those which grow in crowded planta- 

 tions. 



The table of distances applies equally to the thinning of 

 woods. It is divided into four divisions, and each division into 

 three columns. The first column in each division is the distance 

 in planting; the second the number of trees per acre; the third 

 the height in feet and inches at which the different thinnings 

 should take place. The trees at 2 ft. 6 in. distance, 6969 per 

 acre : thinning to commence when these are 9 ft. 6 in. in height, 

 according to the first column in the second division. Trees 

 at 5 ft., 1742 per acre: second thinning should commence when 

 16 ft. 2 in. in height. Trees at 10 ft., 435 per acre : third thin- 

 ning should commence when 30 ft. 4 in. in height. Trees at 

 20 ft., 108 per acre: at this distance trees have sufficient room 

 to attain to the height of 57 ft. 2 in. 



[In the Farmerh Register^ published at Glasgow some years 

 ago, is given an engraved illustration of Mr. Cree's mode of 

 planting and thinning trees ; but, as we do not think it necessary 

 to the understanding of Mr. Cree's very plain and excellent di- 

 rections, we have omitted it.] 



The theory adapted to the practical principles of thinning mixed 

 woods and plantations is calculated to inches, and demonstrated 

 on the same plan : if it makes the nearest possible approximation 

 to practical correctness, it is all that can be expected. When 

 trees are planted at 2 ft. 6 in. distance, and have risen to the 

 average heisjht of 9 ft., then each alternate tree of each alternate 

 row, that is at the height or above the height of 9 ft., should be 

 taken out : those below this height may stand till they arrive 

 at it. 



When any part of a plantation is much exposed to the wind, 



1 or 2 feet, or thereabouts, should be taken off the tops of the 

 trees intended to be cut, this being the most effectual way of re- 

 taining the shelter, and protecting the others from the effect of 

 high winds. 



Next season continue the thinning of the next alternate rows 

 on the same plan ; and the trees that had been left formerly 

 from not being 9 ft. high, if now that height, may be taken out 

 or shortened. The trees will now be (mostly) distant 5 ft. by 



2 ft. 6 in. 



Three or four seasons afterwards the trees may be 1 4 ft. high ; 

 then the alternate rows which have been thinned must have 

 those left on account of shortness either taken out or shortened. 



