48 THE NEW FORESTRY. 



canopy ; shelter to the stems of the trees from both being of 

 the utmost consequence. The trunk of a tree in a dense 

 forest is regarded as but the channel between the soil and 

 living branches high up at the top of the tree, where growth 

 and elaboration is carried on. In the tended forests of 

 Germany, thinning is seldom attempted before the trees are 

 from twenty to thirty years of age, in the case of firs, while 

 hard woods, like the beech, coming up naturally in dense 

 masses, are often left unthinned for thirty-five or forty years. 

 When thinning is done, the greatest care is taken to preserve 

 the overhead canopy, and exclude air currents and winds, 

 even dead trees being often left standing if their removal is 

 going to create a gap. Crowding at all stages is the 

 rule, the live top of branches decreasing in proportion 

 as the trees grow older, until, at the end of the rotation 

 period, in the case of the spruce, only about one-sixth, 

 or even less of the entire length of the tree will be 

 furnished with branches, forming just a tuft at the top, the 

 trunk by this time having long shed its lower branches, and 

 formed a clean straight pole with very ljttle taper from end to 

 end. In the case of hard wood the proportion of top is much 

 the same, a mere wisp, comparatively, carrying on all the 

 functions of growth successfully to the end. However small 

 the top of live branches may be, within reasonable limits, it 

 is sufficient to add a layer of timber to the trunk annually, and 

 given the required number of years a tree of the required 

 dimensions is produced. Big trees of mature timber are not 

 so much sought after in Germany as trees of moderate girth 

 and of good useful quality. A crop of pit-props, for example, 

 averaging from five to six inches quarter-girth in the middle, 

 can be produced in from twenty-five to forty-five years without 

 any thinning at all, but trunks larger and thicker are also 

 produced from forests which have been sparingly thinned a 

 few times in the course of the whole rotation period. Increment 

 of bole depends upon the amount of living top of branches 

 and foliage the tree is allowed to carry, and between youth 

 and middle age, or even later, these may be permitted to 

 increase, when thick trunks in the mature crop is an object, 

 consistently with the preservation of the overhead canopy. 

 From the British forester's point of view, what appeared 

 objectionable to us in those German forests was the large 

 proportion of under-sized trees existing in the middle-aged 

 and even older crops. We do not mean short trees, for all 

 were tall and clean, but under-girthed, slender-stemmed trees, 



