516 TRANSACTIONS AND PROCEEDINCIS OF THE [Sess. lvii. 



((■) Yew at Ormiston, East Lothian (18 34, Sir T. Dick 

 Lauder; 1879, Professor Balfour). 



The estimation of the age of gigantic yews presents 

 peculiar difficulties. Xo opportunity of counting their 

 rings throughout can be expected, as not only is their 

 little chance of such veterans being cut down, but the 

 chance is equally small of finding the mass of the interior 

 preserved from decay. To ascertain their present rate by 

 "irth measurement, at least within a moderate period of 

 years, is scarcely possible, from the extreme irregularity of 

 the surface, particularly at the usual narrowest point, near 

 the ground. We are reduced, therefore, to such informa- 

 tion as can be got from young trees, supplemented by 

 borings at the surface of aged specimens. From the few 

 reliable data collected by Sir E. Christison, he drew up the 

 following scale of probable age for a yew 22 feet in girth. 



This estimate, however, is founded on the supposition 

 that the giants grow only at the average ascertained rate 

 in early life, and fall oil" gradually from an early period to 

 the very slow rate, ascertained by Mr. l^owman's borings, 

 of from 140 to 180 years for the last 18 inches of girth- 

 increase in two yews 22 and 27 feet in girth. But two 



