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which are found in many places, some of them approximating 
four feet in trunk diameter, or perhaps even larger. The slow 
growth of this tree after its first hundred years of life would make 
it probable that some of these monsters were at least saplings 
before the end of the sixteenth century. The average increase 
in diameter of the white oak as calculated from i thickness of 
annual wood rings of trees cut on Staten Island some years ago, 
0.18 inches up to the age of 47 years. Subsequently, the 
ie of wood annually laid on is much thinner. Observations 
on the largest white oak within the grounds of the Garden, 
growing in the woods south of the Museum Building along the 
path leading to the waterfall near a cluster of sweet birches show 
that its circumference, measured July 30, 1909, at four feet above 
the ground, is 11 feet and 2 inches; its diameter is therefore 
about 42% inches and its radius 2114 inches; allowing for the 
thickness of the bark the radius of wood is about 20 inches, A 
little piece was taken out from the side of this tree with a sharp 
chisel and the wound made carefully covered with tar. The 
number of wood layers to the inch as revealed by this ap araiiey 
is 16, the average thickness of the layers being thus 0.062 inches. 
From these observations and other data it is estimated ae the 
average thickness of the annual wood layer of the white oak in 
trunks up to 42% inches in diameter is approximately 0.09 
inches, which would indicate that this individual tree is about 220 
years old. It would therefore seem that white oaks with a wood- 
radius of from 25 to 27 inches would be 300 years old. 
A third feature of the codperation will be an illustrated lecture 
on the native trees of the Hudson River Valley to be delivered 
at the Museum Building of the Garden on the afternoon of Satur- 
day, October 30, at four o’clock. 
N. L. Britton. 
