62 THE ADIRONDACK BLACK SPRUCE. 



In the office of the Forest Commission there are some carbon 

 paper impressions showing growth rings taken from the stumps 

 of spruce trees recently cut by lumbermen trees which were 

 growing in a spruce forest that had been lumbered 24 years ago, 

 at which time all the larger spruce was taken out. The acceler- 

 ated growth of the young spruces which were left, due to the 

 admission of light and air through the removal of the large trees, 

 is plainly seen in the wider rings shown by the carbon impres- 

 sions taken from the stumps. Up to and just preceding the time 

 when the lumbermen first went into this forest these spruces 

 were growing at a rate of 26 rings to the inch. Immediately 

 after this thinning and interlucation there was an increased 

 growth, as shown by the impression paper, at the rate of 11 rings 

 to two inches. 



We regret exceedingly that we are unable to reproduce in print 

 these impression papers of tree rings so as to furnish them with 

 this publication, for they argue plainly and incontestably as to 

 the increased product and revenue which can be derived from our 

 spruce forests where the cutting is done under an intelligent 

 system. 



That the number of rings disclosed by the cross-section of a 

 tree-trunk indicates the years of age is a generally accepted fact. 

 It is so taught in all text-books pertaining to the subject. Asa 

 Gray states that " the trunk of an exogenous tree, when cut off 

 at the base, exhibits as many concentric rings of wood as it is 

 years old." 



Emerson* says of these tree rings that " a single circle attains 

 maturity, in temperate regions, every year." 



Goodalef states that this tk development of the film of growth is 

 usually continuous in a given season, but it may be interrupted, in 

 which case it is possible to have two rings added to the wood in 

 a single year, whereas, as everyone knows, there is usually only one 

 new ring for each year's growth" 



The " interrupted " growth just referred to is the result of a 

 period of cold weather acting upon trees which in the same sea- 

 son have felt previously the influence of an early spring. But in 



* Trees and shrubs of Massachusetts, by George B. Emerson. 



t Garden and forest, Vol. IT, March 20, 1889: Principles of Physiological Botany, as applied 

 to Forestry; by George Lincoln Goodale. 



