4 
rings. In densely shaded or otherwise stunted timber, also in timber 
injured by coal smoke, a similar irregularity has been observed as 
regards the number of rings in different sections, so that a given ring, 
or year’s growth, was found developed 20 feet from the ground but 
entirely absent near the stump of the same stem, thus misleading in 
a consideration either of age or rate of growth. 
At times, especially in extremely stunted timber, it is difficult to 
decide whether a given ring is really a year’s growth or not. The 
difficulty in such cases is sometimes due to a formation of ‘‘ false” 
summer wood, a dark band passing through the light-colored part of 
the ring, resembling the true summer wood, but being separated from 
this by a hghter colored band. This leads to a “‘ false” ring quite fre- 
quently occurring, even in thrifty timber, and always subject to being 
detected by sufficient magnification. In other cases it is the imperfect 
development of the rings carried to such an extreme that the entire 
ring is only one to three cells wide. This case, which occurs only in 
extremely stunted growth, is practically beyond remedy, the rings 
furnishing here only an approximate instead of an exact record of age. 
A much less common case still isa regular duplication of the rings in 
woods like oak, ash, etc., due toa defoliation in midsummer. It has 
long been shown that such a duplication is possible, but cases where 
such rings possess the normal appearance, even in the stem, are so 
rare that they require no special mention in this connection. 
In the determination of the age of a tree, or of a particular sec- 
tion, it is desirable to make a clean, smooth cut; and in trees like 
poplar and willow, and even in birch, it is most convenient to cut out 
the particular cross section and allow it to dry before the counting is 
attempted. In many woods, if of thrifty growth, a clean saw cut 
is sufficient, and the aid of the knife may be dispensed with. Gen- 
erally a magnifying glass of some kind is helpful, and in many cases 
indispensable, while with extraordinary specimens even a compound 
microscope will be needed. The counting is best done along the 
greatest radius, since the rings are plainest along this line; all coy- 
ered wounds or other obstacles should be avoided. It will also be 
found helpful to mark every tenth or twentieth ring with pencil to 
avoid repetition in case of interruption; and zones of very narrow 
rings, such as occur in the outermost portions of old stems, will 
usually require repeated counting. 
Since a seedling of White Pine, for instance, is only about 1 foot 
high when five years old, and since the parts of this five-year-old 
seedling are never raised upward by growth, all growth being by 
addition of new parts, a cross section 2} feet from ground does not 
include this five-year-old tree at all. If the number of rings on the 
stump section is 100, the real age of the tree is not 100 years, but 100 
plus about 6, or 106 years. 
