48 Yew- Trees of Great Britain and Ireland 



deformed by knobs and excrescences that they 

 cannot allow of a comparison anywhere else, and 

 that the stem is so covered with young spray that 

 it is difficult to pass a measuring-tape round it, 

 except at the ground. To this it may properly be 

 objected that in trees such as those at Dryburgh, 

 Roseneath, Yattenden, Sanderstead, and many 

 similar ones elsewhere, the swell of the roots is so 

 ofreat that measurement at the orround-line would 

 make the age appear to be greater than it really is — 

 in some instances as much as one-third ; whereas 

 in other cases, as that of Darley Dale, the increase 

 at the ground-line in sixty years is nil, while the 

 trunk has grown beyond the rate of young trees. 

 There is in trees grown in churchyards another 

 objection to this point, viz., that the ground-level 

 is continually rising. On the other hand, trees 

 growing in exposed situations often have the soil 

 scraped away by animals and the roots exposed. 

 For these reasons the ground-line is very unre- 

 liable. The best point of comparison is at 3 feet 

 from the ground ; but in practice it is as well to 

 take the ground-line in addition. 



The following Table gives a number of examples 

 of the ground-line yielding a larger girth than the 

 higher level, and proves that this is not the best 

 point for measurement : — 



