FORESTRY BUREAU. 



151 



It will be seen that the annual growth is very irregular; this is caused 

 by irregular seasons — some propitious, others contrary. The concentric 

 rings in young trees are readily distinguished by the propitious or ad- 

 verse season. 



As the trees advance in age the inner rings decrease in size and 

 almost disappear, and the growth of the tree diminishes after certain 

 periods. Four beeches mentioned by Loudon show greater variability. 

 One in King's County, Ireland, at sixty years, was 17 feet; one at Fos- 

 ter Hall, at one hundred years, was 12 feet; one at Contachy Castle, 

 at one hundred and two years, was 18 feet; and one at Collander Park, 

 at two hundred years, was 17 feet. Here are three about the same size ; 

 one is sixty years, another two hundred. This variability is still more 

 conspicuous in the oaks. De Candolle, the Swiss botanist, counted the 

 rings of several oaks that had been felled; one at two hundred years 

 had attained the same circumference as another had at fifty. Some 

 had grown slowly at first, then rapidly; others grew rapidly at first, then 

 slowly. An oak three hundred and thirty-three years was shown to 

 have increased as much between three hundred and twenty and three 

 hundred and thirty as it had between ninety and one hundred years. 

 This reduces the computation of the age of an oak to little more than 

 guess-work. 



The Cowthorpe oak, the largest in England, reached 78 feet in cir- 

 cumference. Damory's oak, in Dorsetshire, was only 10 feet less when 

 it was so decayed that it was cut and sold for fuel in 1755. The Don 

 nington oak, in the vale at Gloucester, was 54 feet at the base when 

 burned down in 1790. It is therefore obvious, from the variable rate of 

 growth, that the size establishes no indisputable title to age. 



The following statistics from Loudon show great variability in the 

 growth of oaks : 



Yean. 



Circum- 

 ference. 



Years. 



Circum- 

 ference. 



40 



Feet. 



8 

 12 

 12 

 18 

 21 

 14 

 15 



,200 



Feet. 



25 

 21 

 20 



m 



33 

 27 



83 



200 



100 



201 



100 



220 



100 



250 



120 





180 



! 330 







When, therefore, Gilpin, in his 11 Forest Scenery," speaks of nine hun- 

 dred years as no great age for an oak, it must be said that few can be 

 named whose measurement would sustain the assertion. 



In the matter of concentric rings, personal observation shows black 

 locust, six years, with 12 rings ; shellbark hickory, twelve years, 21 

 rings; pig hickory, six years, 10 rings; wild crab-apple, five years, 11 

 rings; chestnut oak, twenty-four years, 20 rings; American chestnut, 

 four years, 9 rings ; peach, eight years, 5 rings. 



Dr. A. L. Childs, a gentleman of practical science and observation, 

 in a contribution on "Concentric rings," published in the Popular 

 Science Monthly, December, 1883, says : 



In June, 1871, he planted a quantity of red-maple seeds, transplanted them in 1873, 

 in 1882 cut out some. From day of planting to cutting was eleven years and two 

 months. On one he counted forty rings very distinct, none less than thirty-five. 

 The rings were distinct when the tree was first cut, and no mistake could possibly be 

 made. 



