86 ESSAYS. 
alone is known. For often repeated observation proves that 
the increase is greatest, in other words, the layers are thick- 
est, in young trees; but that afterwards— after the first 
century, for instance —the tree increases in diameter at a 
much slower but somewhat uniform, or else still decreasing 
rate, which does not greatly vary in different trees of the 
same species. Such estimates would, therefore, always tend 
to underrate, rather than to exaggerate, the age of a large 
tree. But it is unsafe to apply this method to other than 
really venerable trunks; for the growth of a tree is liable to 
great variations during the first century or two; either from 
year to year, or between different individuals of the same spe- 
cies. The injury of a single leading root or branch, or the 
influence of a stratum of sterile soil, may affect the whole 
growth of a young tree for a series of years; while, in an 
older individual, the wide distribution of the roots and multi- 
plication of the branches render the effect of local injuries 
nearly inappreciable, and the influence of any one or more 
unfavorable seasons is lost in the average of a great number. 
Thus the fine Elm in Cambridge, which during the last win- 
ter fell a victim to one of the most fatal and frequent acci- 
dents which in this country interfere with the longevity of 
trees, — having been cut down to make room for a petty 
building, just as it had reached its hundredth anniversary, — 
was fourteen feet in circumference at the height of three or 
four feet from the ground.’ The girth of its more renowned 
and fortunate neighbor, the “ Washington Elm,” is but little 
over thirteen feet ; and it might accordingly be inferred that 
it is some years the junior of the “ Palmer Elm.” But we 
learn from a very authentic source, that the celebrated Whit- 
field, when excluded from the pulpits of the town and college, 
preached under the shade of this tree in the summer of 1744, 
— just a century ago. It is, doubtless, at least one hundred 
1 This ‘‘ Palmer Elm,” as it was called, grew with more than ordinary 
rapidity for the first seventy years ; when, to casual observation, it must 
have appeared nearly as large as when it was felled. For, during the 
last twenty-two years, it had increased only five and one-half inches in 
diameter, that is, at the rate of a quarter of an inch per annum. 
