THE AGE OF TREES. 57 



tween, say, fifteen feet a century at one end and a little over two feet 

 a century at the other. This might be at the following rate, taking 

 each figure for the growth of a century : 15 + 13 + 10 + 8 + 6 + 3+2 = 

 57. By which calculation seven centuries would have been the tree's 

 age when Sir Robert Atkyns declared it to be fifty-seven feet in 1712, 

 an antiquity that would amply satisfy tradition, but could not remove 

 the probability that the tree is not a single trunk, but really a number 

 of different trees that have become incorporated together. 



A somewhat similar theory may be applied to the famous Castagna 

 di Cento Cavalli on Mount Etna, so called because a Queen of Ara- 

 gon and one hundred followers on horseback are said to have taken 

 shelter beneath it from a shower of rain. Brydone, in 1790, measured 

 the circumference to be two hundred and four feet, but it seemed to 

 him that the tree in question, of which only separate trunks remain, 

 was really five separate trees ; and though he professed to have found 

 no bark on the insides of the stumps nor on the sides opposite to one 

 another, yet a more recent traveler states, in Murray's guide-book, that 

 this is only true of the southernmost stem, and that one of the masses 

 still standing does show bark all round it, which would of course prove 

 it to be a separate tree. Of the other large chestnuts on Etna the Cas- 

 tagna del Nave is rather larger than the Tortworth specimen, while 

 the Castagna della Galea is seventy-six feet at two feet from the 

 ground. The rich soil of pulverized volcanic ash combined with 

 decomposed vegetable matter probably enabled them to attain their 

 present size within a shorter period than would be implied by such 

 dimensions elsewhere ; but whether they are five centuries or ten it is 

 absolutely impossible to conjecture. 



The great variability in the rate of growth in trees of the same 

 species is perhaps the most remarkable thing afforded by statistics. 

 We say, for instance, roughly, that the beech grows twice as fast as 

 an oak ; but take four beeches mentioned by Loudon, placing their 

 years in one column and their circumference in another : 



One in King's County at 60 years was 17 feet. 



One at Foster Hall " 100 " " 12 " 



One at Courtachy Castle " 102 " "18 " 



One in Callendar Park " 200 " " 17 " 



So that of three beeches nearly the same in size one was only sixty, 

 another one hundred and two, and another as much as two hundred. 

 And this variability of rate is still more conspicuous in the oak. De 

 Candolle, who counted the rings of several oaks that had been felled, 

 found one that at two hundred years had only the same circumference 

 that another had attained at fifty. Some had grown slowly at first, 

 and then rapidly ; others, like bad racers, had begun fast and ended 

 slowly. And even the diminished rate of growth would not seem to 

 be an invariable rule, for one oak of three hundred and thirty-three 

 years was shown to have increased as much between three hundred 



