Nov. 1892.] BOTANICAL SOCIETY OF EDINBUEGH. 471 



o in. in girth; lastly, of 0'69 for 97 years in a tree 

 20 feet 1 in. in girth, are recorded. 



Taking the most favourable figures, we may construct 

 the following scheme for a tree 20 feet 1 inch in girth, 

 like the Methven oak (2 c). 



Increase in Girth. 

 From 



Thus we get 285 years as the 'possible age of an oak 

 20 feet in girth, which has grown at the greatest rate that 

 our tolerably reliable data supply, or O'SO. The period 

 might indeed be considerably reduced if we accepted the 

 rate of the Methven oak, between the girth of 14 feet 

 6 in. and 16 feet, as correct. Frequent measurements 

 of this tree, although at irregular intervals (of which I 

 have given only a summary in the table), have been 

 recorded for the past 97 years, and although there are 

 no means of checking their accuracy, and 1*12 at the 

 size mentioned seems an extraordinary rate, yet the form 

 of the stem is such that a considerable shifting of the 

 point of measurement would apparently not cause serious 

 error, over a long period of time. Accepting the 

 rate of 1*12, and without making any allowance for the 

 rate having been greater previous to the tree attaining 

 14 feet 6 in. in girth, the age of this 20 feet oak would 

 be about two and a half centuries, but allowing for a 

 greater rate in its earlier life it would not be much 

 above two centuries. But at the size of the Methven tree 

 the Cowthorpe oak had still 15 feet 8 in. to grow, and 

 supposing the rate during this latter period reduced to 

 half that which brought the tree in our scheme to 20 feet, 

 or 0"40, and adding upwards of a century, during w^hich 

 decay is known to have been going on, the age of the 

 Cowthorpe tree would be 855 years. It could not well 

 be less, except on the supposition either that such a giant 

 does grow throughout more quickly than at the quickest 

 rate ascertained for smaller trees, or that the rate, instead 



