5 8 THE POPULAR SCIENCE MONTHLY. 



and twenty and three hundred and thirty as it had between ninety and 

 one hundred. 



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

 than guess-work. The Cowthorpe oak, the largest existing in Eng- 

 land, reached at one time seventy-eight feet in circumference. Da- 

 mory's oak, in Dorsetshire, was only ten feet less when it was so 

 decayed that it was cut up and sold for fire- wood in 1755 ; and the 

 Boddington oak, in the vale of Gloucester, was fifty-four feet at the 

 base when it was burned down in 1790. It is needless to mention other 

 English oaks which are also claimants to a remote antiquity ; but it is 

 obvious, from the very variable rate of the growth of oaks, that size 

 establishes no indisputable title, and that the Cowthorpe oak need not 

 therefore be the oldest English oak because it is the largest recorded. 

 From Loudon's statistics of oaks are extracted the following notices 

 of trees, according to their age and girth : 



Feet of 

 Tears. circumference. 



40 8 



83 12 



100 12 



100 18 



100 21 



120 14 



180 15 



Feet of 

 Years. circumference. 



200 n 



200 25 



201 21 



220 20 



250 '.. 19* 



300 33 



330 27 ' 



This table not only shows the great variability of growth, but, if we 

 take the three specimens of one hundred years old, gives us the high 

 average of seventeen feet as that of only the first century. Taking, 

 then, as usual, the third as the average growth, we should require 

 rather more than eight centuries for an oak of fifty feet, which re- 

 duces to a very small number the oaks in England that can claim a 

 thousand years. 



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

 hundred years as of no great age for an oak, it must be said that very 

 few oaks can be named which by measurement would sustain their 

 title to that age. Tradition, which is always sentimental, leans nat- 

 urally to the side of exaggerated longevity. William of Wainfleet 

 gave directions for Magdalen College, Oxford, to be built near the 

 great oak which fell suddenly in the year 1788, and out of which the 

 president's chair was made, in memory of the tree. Gilpin assumes 

 that for the tree to have been called great it must have been five hun- 

 dred years old, and, therefore, perhaps standing in the time of King 

 Alfred. But it is clear that it need not have been a century old to 

 have fairly earned the title of great, and that, therefore, a period of 

 six centuries may have covered its whole term of existence. 



We are certainly apt to underrate the possible rate of growth 

 where a tree meets with altogether favorable conditions. The silver 

 fir was only introduced into England in the seventeenth century by 



