i 4 TIMBER AND TIMBER TREES. [CHAP. 



tapering or conical form (Fig. 6), and elongating them- 

 selves year by year, so that a large proportion of those 

 visible at the butt are traceable at the upper part of the 

 stem. A given diameter of wood consequently contains 

 many more layers at the top than at the butt end of 

 the tree. 



The following table is given to show the number of 

 concentric rings counted in the butt and top ends of 

 four very fine English Elm trees : 



TABLE I. 



From the examples here given, we find that about 

 84 per cent, of the layers seen at the butt were trace- 

 able at the part where the tree was topped off. We also 

 see by the number of layers in one inch of wood at the 

 top, as compared with the butt end, the approximate 

 taper of the cones just referred to. 



It is very generally admitted that, in latitudes having 

 the seasons clearly defined as they are in this country, 

 each circle of lignine is completed in one year, but 

 opinions differ as to this being the case in tropical 

 climates, and there are botanists who consider that as 



* This tree, when cut at 25 feet from the butt, was found to have 

 ninety-two layers at that point. 



